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Definitions from the acoustics and sound technology

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absolute hearing

see #absolute pitch

absolute pitch

Absolute pitch (ger. Absolutes Gehör) is a person's ability to pitch (identify) any clear sine tone frequency (musical note) without an external reference.

  • Remark: The identification of emerging permissible error variance has to be specified (see Perfect pitch).
  • Remark: Mostly a musical note is identified not a frequency value.
Absolute threshold, hearing threshold Hörbarkeitsschwelle

(Engl. absolute threshold, threshold of audibility, threshold of detectability; hearing threshold, Absolute threshold):

  1. The absolute minimum threshold is the charm, in a specified proportion of experiments causes a response.
  2. The smallest sound pressure level, a hearing must be sound to repeated attempts at a frequency of 50% (75%) to be heard [NTG 1704], [DIN 1320].
  • Note 1: Instead of the method of constant stimuli (Constance method), by the English wording. a specified proportion of experiments) implies, may psychophysical another method (which should be specified).
  • Note 2: When listening is hearing an example of an absolute threshold.
  • Note 3: When listening are the characteristics of the signal, the type of performance (for example, monaural, binaural etc.) and the point at which the sound pressure level is measured, indicated.
  • Note 4: Unless otherwise noted, the environmental noise, in the Meßsituation to the ears auftrifft considered negligible.
  • Note 5: The individual hearing threshold is generally in dB SPL (relative to 2.10-5N/m2).

Adaptation (ger. Adaption) ...

Adaptive psychophysical method

A psychophysical adaptive method (ger. adaptive psychophysikalische Methode) is primarily for the determination of thresholds set up for this procedure is the charm size depending on the response of the subject to the previously stated charm. The size can be a stimulus) under the direct control of the subject, or b) it is the investigator adjusted depending on the number of previously delivered right or wrong answers.


(Ger. Beschleunigung): acceleration is a vector of the change of speed.

  1. Acoustics (Engl. Acoustics) is the science of sound, including its production, transmission and effects.
  2. The acoustics of a space is the totality of those properties that a particular sound field characteristics, and thus a sensation cause hearing.

The qualifying word acoustic properties (Engl. acoustic, acoustical) means producing, arising from, as updated by, in relation to, or associated with sound, in short, the sound on. In English acoustic used in the technical sense, if the term should refer to something that is compatible with the properties, size or physical characteristics of the sound waves associated. Acoustical is needed if the qualifying term is not explicitly such properties, size or physical characteristics. The distinction between acoustic and acoustical is not in German.

  • Note 1: Examples of the name are acoustic physical terms such as impedance, Inertanz, cargo, sound power, energy, wave, medium, signal transmission, absorption, transmission, etc.
  • Note 2: acoustical is used, if not directly a physical reference is to be created, such as: Society, method, engineering, education, glossary, a symbol, problem, measurement, point of view, use, investment, standards, etc.
Acoustic reflex

(Engl. stapedius reflex, tensor tympani reflex), see Stapedius, Tensor Tympani

Acoustic trauma

An acoustic trauma (Engl. acoustic trauma) is a violation of the ear, caused by a sudden and intense acoustic charm of a temporary hearing loss or permantenten to some extent.

  • Note 1: Explosionsknalle or other intense noise events are examples of such stimuli.
Acoustic shadow

see sound shadow

Acoustic scattering

Acoustic scattering (Engl. acoustic scattering) is the irregular reflection, refraction or diffraction a sound in many directions.

Air-hole bone conduction

(German air-bone gap; air-bone conduction hole): An air-bone conduction hole for one ear at a specified frequency, is the difference in decibels (dB) between the level at the hearing threshold for air line and bone conduction.

  • Note: The measurement must be specified.
Air Line

(German air conduction; Air Line): Air Line is the process whereby the sound through the ear canal (Engl. external acoustic meatus;) as part of the transmission path led to the inner ear.


Algorithm (Engl. Algorithm; algorithm): An algorithm is a systematic procedure for evaluating a mathematical function; quantitative model. [PAR]

Allpaß network

Allpaß Network (Engl. All-pass network; Allpaß Network): A Allpaß Network is a network, which phase shifts or time delays introduced without a significant slowdown at any frequency cause.

ambient noise

(Engl. ambient noise, ambient noise): Ambient noise is the all-inclusive noise, with an environment is usually a combination of many Schällen from near and far located sound sources.


Amplitude (Engl. amplitude; amplitude): amplitude is the peak (peak) value of a function, see Peak, RMS, Average amplitude.

Amplitude spectrum

Amplitude spectrum (Engl. amplitude spectrum; amplitude spectrum): The amplitude spectrum of a time is a function describing the same in their components, each with a different frequency and (usually) different amplitude (see spectrum, phase spectrum).


Anacusis (syn deafness).


Analysis (Sheet Analysis; analysis): The term analysis is in the psycho-acoustics mainly used in the following context: a) spectral analysis and time, b) Analytical listening and c) Musical analysis. [PAR]

Analytical Listen

Analytical Listening (Engl. analytical listening; Analytical listening): analytical listening is the way a sound sensation in one or more components of a complex sinusoidale Tones (sound) diskriminativ be heard, the sensation of sinusoidalen components outweigh the overall sensation of sound allowing several pitches simultaneously heard. The ratios between the different pitches are affected more by commonality pitch by pitch as close. [PAR]

Anchor attraction

Anchor attraction (Engl. anchor sound; anchor attraction): Under the anchor attraction is the invariant attraction, which - usually in a psychoacoustic experiment - with a number of stimuli compared, in one or more stimulus sizes differ. [PAR]


Antiphasig (Engl. Antiphasic; Antiphasig): Antiphasig refers to the condition in which the stage or the time difference of the signal, which is offered each ear, is a fixed, different from 0 value of the phase or the time difference a noise at each Ear is different.

  • Note: An example of a antiphasige condition is such that when the phase of the signal in one ear, relative to other vice versa (opposition), while the phase noise in both ears is offered.

Anti-resonance (Engl. antiresonance; anti-resonance): For a system in forced anti-vibration resonance exists at a point when even the smallest change in the excitation frequency an increase in system response (response) at this point causes.


Atonal (Engl. atonal; Atonal): With atonal music that is described in the harmonious relationships should be avoided (eg Zwölftonmusik), it follows that little or no sensation of a tonal center. [PAR]


Attitude (Engl. attitude; Attitude): Different way of a sound sensation, for example: analytical versus holistic, spontaneous, versus inzidentell willingly, intentional, etc. [PAR]


Attribute (Engl. audio frequency; audio frequency): An audio frequency is every frequency to a normally audible sound wave.

  1. The range of audio frequencies is (roughly) between 15 Hz and 20000 Hz
  2. The word audio can also be used to a device or a system to designate which in the field of audio frequencies; example: audio amplifier.

(Engl. audibility; audibility): The audibility individual spectral pitches part of a sound tones by the Hörbarkeitspegel or level surplus (Engl. SPL Excess). A surplus level> 0 means that the question Teilton a Spektraltonhöhe. [TER].

Audio grams thresholds

Audiogram, emerging audio grams (Engl. audiogram, audiogram threshold; audio grams): An audio grams is a curve, the hearing loss as a function of frequency.

Audio grams masking

Audiogram, masking audio grams (Engl. masking audiogram; audio grams, Maskierungs): A mask audiogram is a graphical representation of masking the noise by a particular cause. The curve shows the masking in dB as a function of frequency of the masked sound.

Aurale Harmonic

Aurale Harmonic (Engl. aural harmonic; Aurale Harmonic): See harmonics, aurale.


Auditiv (Engl. auditory, auditory; Auditiv): The qualifying property auditory word means hearing relating to the hearing related gehörmäßig.

Auditorisches System (Engl. auditory system; Auditorisch). Psychophysiologisches system, ear, auditory nerve (Engl. auditory nerve), and auditory pathway cortex (Engl. auditory pathway, auditory area;), including where the hearing process expires.

Auditori rulers electricity

Auditori rulers current (Engl. auditory stream; Auditori current ruler): In the hearing sensation to gestalthaften elements zusammenfaßbare Warhnehmungsinhalte, the horizontal (ie in their time) deliberately structured.

  • Note: Auditory streaming improves the visibility of complex signals, with relevant and irrelevant information parameters separately processed.
Average, geometrically

(Engl. geometric mean; Geometric mean): The geometric mean value of a degree distribution of figures is equal to the nth root of the product of values, where n is the number of distribution contained values. The geometric mean value is a measure of central tendency.


background noise

(Engl. background noise; background noise): As the background noise is the sum of all sources of interfering in a system which is intended for the production, detection, measurement, or recording a signal, regardless of the presence of the signal.

  • Note 1: environmental noise, detected, measured, or taken with the signal is a part of the background noise.
  • Note 2: In this definition is included interference, primarily from the power supply and usually results Brumm (hum).
ball wave

(Engl. spherical wave; ball wave): A ball wave is a wave at the wave fronts concentric spheres (see spherical wave).


The nominal bandwidth (ger. Bandbreite) of a filter is given by the difference between the upper and the lower cut-off-frequency. This difference may be expressed (1) in Hertz, (2) as percentage of the center frequency of the pass-band or (3) as the interval defined by the upper and lower cut-off-frequency in octaves (i.e. 1 octave, 1/3 octave)

  • Remark: For more definitions see also USA Standard Method for Specifying the Characteristics of Analyzers Used for the Analysis of Sounds and Vibrations, Z24.15-1955
band power level

The band power level (ger. Band-Leistungspegel) of a sound for a specific wave band is the sound power level of a sound within a limited wave band.

band pressure level

The band pressure level (ger. Band-Schallpegel) of a sound for a specific wave band is the sound pressure level of a sound within a limited wave band.

  • Remark: The wave band may be specified by its lower and upper cut-off-frequency or by its pass-band and the bandwidth. The bandwidth of the band may be specified as follows: octave-band (sound) pressure, half-octave-band pressure, third-octave-band pressure, 50-Hz-band pressure.

(Engl. Bark, Bark): Bark is the unity of the Tonheit. The frequency bandwidth of a frequency group (critical band), 1 Bark (named after Barkhausen).

  • Note: The scale of the Tonheit in Bark can from the frequency in Hz approximated calculated as follows (frequency (f) in kHz, arctan in Radiant):
  • Zc / Bark = 13 arctan (0.76 f / kHz) + 3.5 arctan (f / 7.5 kHz) 2

(English bass; bass): Lowest note a chord (see chord root); low frequency or pitch register. [PAR]

Bulk Acousic Wave (BAW)

An acoustic wave that travels through a piezoelectric material, as in a quartz delay line. Also known as volume acoustic wave.

see also Surface Acousic Wave (SAW)

(Engl. binaural; Binaural): Binaural refers to beidohriges hearing.

Binaural Schwebungen

(Engl. binaural beats; Schwebungen, binaural): Under binauralen Schwebungen is the phenomenon that two (primary) sounds using frequencies f1 and f2, each ear separately offered a periodic change in the degree of Lateralisation generate the rate of Change is done with the Schwebungsfrequenz of the resulting Sekundärtones (f1 - f2), see also Drehton. [BEK]

Binaural Diplakusis

(Engl. binaural diplacusis; Diplakusis, binaural): Under the condition otologischen Binaural Diplakusis calls a sine wave same frequency a different pitch in one ear and out the other.

  • Note: Binaural Diplakusis is a lesser extent also in normal hearing.
Binaurales Trading Ratio

(Engl. binaural trading ratio; Binaurales Trading Ratio): The Binaural trading ratio is the size, which is determined by adjusting the arrival time and / or pressure levels of the two ears dichotisch presented stimuli, so the sound lateralisiert to the median level of the head. The Binaural trading ratio is formed from the interauralen time difference in microseconds divided by the sound pressure level in decibels difference.



(English category; category): subdivision of a continuum (such as Category 5, the real numbers in the range of 4.5 to 5.5); group together related words (such as tools: hammer, pliers, saws); area of sensory attributes (eg Gradations of blue). See categorical perception.

combination Ston

(Engl. combination tone; combination tone):

  1. A combination tone is a (secondary) tone that can be perceived when two loud (primary) sounds simultaneously presented. The Sekundärton can Differenzton or Summationston. A single pair of primary tones various combination can produce sounds.
  2. Combination sounds occur during the superposition of two or more sine tones in a nonlinear transmission system in addition [NTG 1704].
  • Note 1: combination tones can also be heard in aurale harmonic system.
  • Note 2: combination tones are by the nonlinear properties of the hearing founded.
  • Note 3: The term primary and Sekundärton is different from the masking experiments. Sekundärtöne are masked tones.
  • Note 4: A Differenzton is a combination sound with a frequency that is the same frequency difference between the frequencies of two primary tones or their overtones. A Summationston is a combination sound with a frequency that is equal to the sum of the frequencies of two primary tones or their overtones.
Complex sound

(Engl. complex tone; Complex sound):

  1. Under a complex sound is a sound wave, the simple sinusoidale components with different frequency and amplitude usually different (see sound).
  2. A complex sound is a sound sensation caused by more than one pitch is characterized (see sine wave, sound).
  3. A complex Tonkomponente (Engl. complex tone component; Tonkomponente Complex) is a complex tone as part of a sound (a musical note, a chord).
  4. A complex Tonempfindung) (Engl. complex tone sensation; Tonempfindung Complex) is the perception of a single pitch in the performance of complex tones (see Virtual pitch).
  • Note: The frequencies of the components of a complex sound can be used in a fractional ratio (or nearly whole) to a fundamental frequency are common (see harmonic sound). In this case, the waveform (almost) periodically and a single pitch is pronounced audible.
component, Tonale

(Engl. tonal component; tone): Under a tonal component is a waveform (usually periodic), which together with other components tonal (and possibly noise) added a new wave form (usually a realistic sound) is (see Teilton). [PAR]


(Engl. masking; concealment): syn masking.


(Engl. conditioning; conditioning):

  1. Regular and influence invariant aspects of the environment on cognition.
  2. Learning induced reactions.

(Engl. confidence interval; CI): Konfidentintervall (confidence) is at a given distribution function, a variable range of values within which a certain percentage of the observations with a specified probability to lie, (eg normal distribution, 95% CI).


(Engl. consonance; consonance):

  1. Consonance is the phenomenon whereby a joint Samaritans sounds pleasing and pleasant sensation cause. [ANSI].
  2. Consonance includes the degree of good Zusammenklingens simultaneously or in a sequence presented tones. [PAR]
  3. Consonance is the harmony an independent, no resolution bedürfender harmony with predominantly koinzidierenden Teiltonfrequenzen and the resulting high level of merger.
  • Note 1: consonance depends on the roughness of tonality, pitch commonality, of the pitch distance, the context, the familiarity (with the musical material) and cultural conditioning.
  • Note 2: Psycho-Acoustic consonance is primarily by the absence of roughness.

(Engl. context; context):

  1. Context, musical: all sensations which simultaneously available to us, in a special memory chunk of sensory perception.
  2. Context entropy: information content related symbol aggregates (see time window).
Critical Volume

(Engl. Critical Band)

  1. The Critical Band (for the loudness) is the band within which the loudness a continually distributed sound (noise) with constant sound pressure level (SPL) regardless of the bandwidth.
  2. The Critical Band (for escaping)) is that a band sound, a part of a broadband noise with continuous spectrum, which is the same sound as a performance at the center frequency of the strip lying sine wave, in the presence of broadband noise is audible is.
  • Note 1: With just heard is meant audible in a specified number of attempts.
  • Note 2: The use of the Kritischen band to estimate the masking should be restricted to masking by noise with continuous spectrum without excessive peaks or irregularities (in the frequency range) and to cases in which the masking exceed 15 dB.
  • Note 3: For a sine wave in a broadband noise with continuous spectrum is just audible, the level of the sine tone in dB the spectrum of the continuous noise level (at the same frequency) by 10 log10 of the ratio of Kritischen bandwidth (for escaping) Unit bandwidth. The antilog (base 10) by 1 / 10 of Kritischen ratio (Critical ratio) in dB is equal to the bandwidth of the Kritischen band (for escaping).
Critical damping

(Engl. critical damping; critical damping): The Critical damping is the minimum visköser to a damping system allows ausgelenkten to its original position without oscillation (oscillation) return.

Critical Maskierungs ratio

(Engl. critical masking ratio; Critical Maskierungs ratio): See Critical Band, Rekognitions differential.


The cutoff frequency (ger. Grenzfrequenz, Eckfrequenz) is the frequency nearest to the center frequency where the level exceeds ±3dB.


(Engl. cents; cents): The cent is an interval between two tones with a fundamental frequency ratio of zwölfhundertsten root of the 2nd

  • Note 1: The interval in between two cents 1200mal frequencies is the logarithm to the base 2 of the frequency relationship. Therefore, equal to 12 cents in 1200 equal to half tempered tones, like a octave.
  • Note 2:
Cents = 1200. log2 (f2 / f1) = 3.986. log10 (f2 / f1)
Cents = 1200. log10 (f2 / f1) / log10 (2)
Central masking

(German central masking; masking Central): Central masking arises when the masked Schall (Maskee) which offered an ear and the sound maskierende (Masker) the other. The place where central masking is situated on higher levels of the auditory pathway.

  • Note 1: The threshold shifts due to central masking rarely exceed 15 dB.
  • Note 2: Central masking is distinguished from Kontralateraler masking.

A chord (Ger. Akkord) consists of three or more simultaneously erklingenden notes. In general use, the individual components three or four half away (small, large third; triad, Tetrachord, Sept chord).

  • Note: The harmony without taking into account the intervals is called cluster [Moorer, 1975].
chord progress exceeded

Fort chord exceeded (Ger. Akkordfortschreitung) is a sequence of chords, a Fort homorhythmische misuse of sounds, from complex tones are compounded (musically: notes). [PAR]

chord fundamental

A chord fundamental (Ger. Akkordgrundton) is a physically non-existent, virtually added tone in bass frequency range, see Virtual pitch. [TER]

chord class

Under a chord chords class (Ger. Akkordklasse) is those whose grades only by the Chroma (pitch-class).

  • Note: examples of a chord class: CEG, c2-e2-g2 or g1-e2-c3. The chords can be inverted or doubled (see Stimmakkord? .. Chord mood?).
chord close position

Final chord position (Ger. Akkord-Schlußposition), the mood is a chord class with the lowest and the highest grade less than an octave away. [PAR]


(Engl. chroma; chroma): Chroma is a pitch-class without specification of Oktavregisters, the interval in between semitones of the pitch and the nächtstieferen category C is as follows: Chroma of C3 is 0, Des5 1, is of F4 5, etc. [PAR]

Chromatischer circle

(Engl. chroma cycle; chroma): Musiktheoretisches construct of Chroma, a Uhrziffernblatt emulated with C at 12h, Cis in 1h, D 2h etc. [PAR]

chroma saturation

(Engl. chroma salience; chroma): perceptual measure of the importance of a certain Chroma in a musical sound or sound in a sequence, perceived by the average listener or ideal. [PAR]


(Engl. chroma tally; chroma): Calculated average Chroma noticed how often; measure of the chroma saturation.

Chroma probability

(Engl. chroma probability; chroma): Calculated probability of a chroma noticed; measure of the chroma saturation.

chromatic scale

(Engl. chromatic scale; chroma): pitch scale with 12 categories in nearly the same distance within the octave; bercumaural scale; Circumaural). Circumaural refers to the condition: the ear umschließend (eg circumaurale headphones).

Correct rejection warp

(Engl. correct rejection, correct dismissal; Correct rejection warp): Correct rejection or warp is correct in that event detection in a situation during a specified interval observation means in which to a "plain noise" stimulus (input) a "plain - Noise "answer (output) efolgt P (N | n) see also hit, Wrong alarm, correct rejection ..

  • Note: Correct warp and a false alarm close mutuell from each other in a plain noise stimulus.
cutoff, rated, top, bottom

(Engl. nominal upper and lower cutoff frequencies; cutoff): The upper and lower (nominal) cut a filter Druchlaßbereiches (Paßband) are those frequencies above and below the maximum output frequency of a filter, where the output of a signal to sinusoidalen 3 dB below the maximum value.


decay time

Decay time (ger. Abfallzeit) is the time that elapses in which the sound pressure level (or any other characteristic given) by a value drops to another, both values, the starting value and the target must be explicitly set out. A common unit for the description of the decay time of sound is per second decibels (dB / s).

  • Note 1: The decay constant characterizes the exponential course of the sound decay after the sound source was stopped (unit: s-1).
  • Note 2: If p0 the effective pressure at time t = 0 and p(t) the effective pressure at time t, and both follow the relationship: p(t) = p0 * ek * t then k is the decay constant.
decacy time

decay time (ger. Abfallzeit) In general it is the time between a sound pressure level and a lower sound pressure level. Both levels have to be defined explicitly. It is also useful to describe the decay time as speed of lowering sound pressure level (db/sec).

  • Note1: The decay time constant characterizes the exponential decacy of sound after stopping the sound source (Unit: s-1).
  • Note2: If p0 is the effective sound pressure after stopping the sound source at t = 0 and p(t) is the effective sound pressure level at t, and p(t) = p0*e-k*t is imperative, then k is the decay constant.

(Engl. damping; damping): Decay is the transformation (dissipation) of a form of energy into another over time or distance.


(Engl. Decibel; decibels): The decibel is a tenth of a Bel. The decibel is a unit of a level if the base of the 10th logarithm Root of 10 is the appropriate and proportional to the size performance.

  • Note 1: Examples of such sizes: performance (any form), sound pressure squared, particle velocity squared, sound intensity, sound energy density, voltage squared, therefore, is a unit of the decibel sound squared (actually: the level of sound pressure squared), at the practice is simply the expression of sound pressure level used when no likelihood of confusion.
  • Note 2: The logarithm to the base of the 10th Root of 10 is equal to 10 times the logarithm to the base 10; eg applies to the number X2: log10 (1 / 10) X2 = 10 log10 X2 = 20 log10 X. The last term is normally used definition of sound.
  • Note 3 examples: 1 decibels is the sound pressure level of an equal dem10 (1 / 20) times the reference pressure; r decibels is the level of a pressure equal to the r/20) 10 (times the reference pressure, etc.
  • See also Computing with decibels.

(A), (dB (A) A rating): The human ear sounds feels the same pressure, depending on the frequency (pitch) differently loud. Thus, relatively high sounds louder than felt deep tones. To wahrnehmungsgetreue metrological collection of noises to allow the facts of a fre-quency volume sensation in Lärmmeßgeräten by the fact that the occurring of the frequencies to be measured noise in the sound level meter to adapt to the human hearing organ with the help of various filters strongly attenuated.


(Engl. dichotic; Dichotisch): Dichotisch refers to the condition of hearing the sound stimulus to the one ear is presented is different to the other ear offered.

  • Note: The charm may vary in relation to the sound pressure, frequency, phase (time), duration, the bandwidth, etc.

(Engl. difference tone; Differenzton): A Differenzton tone is a combination of frequency equal to the difference between the frequencies of two primary tones or its harmonics (see combination tone).


(Engl. diotic; Diotisch): Diotisch refers to the condition of hearing the sound stimulus to the one ear is fairly presented, is identical to that offered to the other ear.



(Engl. echo; Echo): An echo is a reflection or in some other way (such as artificial) zurückkommende shaft with sufficiently large amplitude and delay, so that they separated (time, maybe even physically) from the shaft directly transferred to be exercised.


(German efficiency, effectiveness):

  1. The effectiveness of a plant in terms of physical size, are either saved or transformed, is the relationship between the output of usable size and the total input.
  2. The effectiveness (eta) of a detector is the signal-to-energy noise ratio (SNR) of an ideal detector divided by the signal-to-noise ratio of the energy is in custody detector, if both detectors the same task to solve.
  • Note 1: Unless otherwise specified, the term refers to performance effectiveness (Power).
  • Note 2: A detector test, a person or another, decisions taken institution.

(Engl. natural frequency; natural frequency): The natural frequency of a system is the frequency with which the system swing. For a system with multiple degrees of freedom are the natural frequencies normal modes of vibration.

Environment noise

(Engl. ambient noise, environmental noise): environmental noise is the all-encompassing noise, which is associated with a given environment, usually composed of Schällen by a larger number of sources from near and far.


(Engl. miss; errors): With error is that in an event detection situation during a specified interval observation means in which to a "signal" stimulus (input) a "noise-only" response (output). An error, for example, if the response event no stimulus event shows even though a stimulus was necessary, P (N | s) see also hit, Wrong alarm, correct rejection.

equal tempered scale

(Engl. equally tempered scale; equal tempered scale): An equal tempered scale is a musical scale, caused by the breakdown of the octave into a certain number (usually 12) equal intervals to distante (cents).

  • Note: the division follows a geometric series.

(Engl. augmented; excessively): Heading for an enlarged musical interval. usually a semitone larger than the perfect interval. Contrary: reduced (Engl. diminished;) .. [PAR]

  1. excessive fourth: interval of 6 half-tones, equivalent to reduced fifth; Tritonus.
  2. excessive fifth: interval of 8 half-tones, equivalent to vermindeter sixth.
  3. excessive triad. ...
  4. übermäßge sixth. ...

(Engl. externalization; outsourcing): outsourcing is the perception, which is a subject allows for a sound event outside of the head and a sound source to identify.

  • Note 1: It is assumed that head movements and the resulting changes in the interauralen sound and the resulting phase differences allow this perception (see head-art stereo).
  • Note 2: by determining the position of appearing made sound source perception is called localization (see localization, auditory).



(Engl. particle velocity; Fast): The Fast (particles speed) or effective particle velocity (root mean-square particle velocity) at a point is the value of the square root of the square means of instantaneous particle speeds over a time interval at one point observed. For periodic particle velocities, the interval a whole number of cycles or the interval must be compared to the corresponding period long. For nichtperiodische particles should speed the interval long enough so that the value received in particular by small changes in the interval length independent.

forward masking

(ger. Nachverdeckung): see also "masking".

filters, wave

(Engl. wave filter, filter).

  1. A (wave) filter is a transformer for the separation of waves on the basis of their frequency. It leads through relatively small losses in the leakage area of one or more frequency bands and relatively large for all other frequencies.
  2. Bandpaß filter (Engl. band-pass filter; Bandpaß filter). A Bandpaß filter is a (wave) filters with a single discount (band) which is a certain critical or (lower) limit will be greater than 0 Hz is up to a finite upper limit.
  3. Hochpaß filter (Engl. high-pass filter; Hochpaß filter). A Hochpaß filter is a (wave) filters with a single discount (band) which is a certain critical or (lower) limit will be greater than 0 Hz, to infiniten frequency.
  4. Low-filter (Engl. low-pass filter; low-filter). A low-filter is a (wave) filters with a single discount (band) which is from 0 Hz to a certain critical or (upper finite) frequency.
  • Note: A Multiple Bandpaß filter consists of two or more Bandpaß filters in parallel circuit.

(Engl. flutter echo; Flatterecho): Flatterecho is a (periodic) Multiple Echo (see Echo).

frequency spectrum

(Frequency): The frequency of a periodic time is the function of the basic Reziprok period (see period). The unit of frequency is the Hertz (Hz).

  • Note: The Hertz is the vibration per second.
Frequency interval

(Engl. frequency interval; frequency interval): See interval.

Frequency group

(Engl. critical band; frequency Group): The group is the one frequency band within which the hearing in the formation of the sound volume intensity, in the formation of a sinus Mithörschwelle sound, the sound intensity interference added see Critical Band [NTG 1704].

Frequency group level

(English band critical level; frequency group level): The frequency group level is the sound pressure level of that sound share, in a certain frequency group falls [NTG 1704].

Frequency pitch

(Engl. frequency pitch; frequency pitch): The frequency pitch is a measure of the pitch. It is gained by a sine wave with a defined sound level using a frequency change on the same pitch as the sound set to be assessed [NTG 1704].


(Engl. frontal plane; Frontalebene):

  1. The Frontalebene is a vertical level, the body in a front and a rear part divided. It is perpendicular to the horizontal plane (median level).
  2. The Frontalebene is a reference level, to describe the characteristics of the hearing is used. It is perpendicular to the horizontal plane and cuts the upper limits of the external auditory canals [NTG 1704].
Frontaleinfallendes free field

(Engl. front-incident free sound field; sound field, frontal): In a frontaleinfallenden, free sound field, the observer directly with the face of a single sound source with free progressive waves attention.

fundamental frequency

(Engl. fundamental frequency; fundamental frequency): The fundamental frequency of a periodic size is the frequency of that component sinusoidalen the same period as the regular size.




(Engl. reverberance; Halligkeit): Under Halligkeit is hearing characteristics of the event, to give the impression that in an area other than the direct sound delayed (eg reflective) is sound, not a repetition of the direct sound is perceived [NTG 1704 ].


(Engl. auditory system; hearing): The auditory system is an organ system that is listening. In humans, is generally a peripheral auditorisches system and a key distinction.

radius Hall

(Hall radius): The Hall radius is the distance from a sound source in a closed room in which the received direct sound energy equal to the received reflected (diffuse) Sound Energy (NTG 1702).

Hallmaß, Hall distance

(Hallmaß): The logarithmic Hallmaß is the ratio of reflected to direct sound energy received (NTG 1702).

Hall room

(Engl. reverberation room; Hall room): A Hall area is an area that has a long reverberation time, and specially equipped to the sound field is located so vague as possible.


(Engl. harmonic; harmonic): A Harmonious is a sinusoidale size with a frequency that an integer multiple of the frequency of a periodic quantity, to which they related.

harmonics, aurale

(Engl. aural harmonic; Aurale harmonic): A aurale Harmonic is a harmonic in the auditory system is formed.


(Engl. hit; matches): hit is that in an event detection situation during a specified interval observation means in which to a "signal" stimulus (input) a "signal" response (output). A hit, for example, if the response event stimulus event shows after a stimulus was necessary, P (S | s) see also Wrong alarm, error, correct rejection.


(SPL excess) (Engl. audible level (SPL Excess); Hörbarkeitspegel): The Hörbarkeitspegel one (sinusoidalen) Part sound a sound is his level of the masked threshold (almost Mithörschwelle, masked threshold) of the sound. The masked threshold is less relevant part of the sound itself. [TER].

hearing sensation

(Engl. auditory sensation; hearing sensation): Hearing is the perception by a hearing on acting sensation caused irritation. The hearing is feeling sensation in sizes divisible.

  • Note: If there is ambiguity, the prefix hearing sensation eliminated. The term hearing sensation is also a synonym for the hearing event.

(Hörsamkeit): Under Hörsamkeit is the suitability of an area for certain sound performances [NTG 1704].

hearing sound

(Engl. audible sound; hearing sound): Audio sound is sound in the frequency range of human hearing (about 16 Hz to 16 kHz). [NTG 1704].

hearing threshold

(Engl. hearing threshold; hearing threshold): syn threshold, absolute.

hearing loss

(Engl. hearing loss, hearing loss):

  1. The hearing loss is a concept that the waste describes the auditory sensitivity.
  • Hearing loss is the difference between the threshold of a listening ear and normal hearing threshold [NTG 1704].
  • Note: As a test sound is usually (intermittent) sine wave (see audio grams). This allows the hearing loss as a function of frequency may be indicated.
horizontal plane

(Engl. horizontal plane; horizontal plane):

  1. A horizontal plane, a reference level, the body into an upper and lower part is divided.
  2. The horizontal plane is a reference level, to describe the characteristics of the hearing is used. It is perpendicular to Frontalebene and goes through the upper limits of the external auditory canals and the lower edges of the eyes caves [NTG 1704].



(Engl. intensity;): See sound intensity.

intensity level

(Engl. intensity level;): See sound intensity level.


(Engl. interaural; Interaural): The property interaural word refers to the conditions that prevail in both ears.

Interaurale intensity difference

(Engl. interaural intensity difference; Interaurale intensity difference): The Interaurale intensity difference in outside the median level is sound events occurs, with the left or right localization evaluated.

Interaurale phases, time difference

(Engl. interaural phase; Interaurale phases, time difference):

  • The Interaurale time difference, when outside the median level is sound events occurs, with the left or right localization evaluated.
  • The Interaurale phase difference is the stage (or time) difference between the signal and / or noise parameters to one ear and the signal and / or noise parameters to the other ear. This difference is usually in reference to a Radiant expressed ear.
  • Note 1: Typical signal (S) and noise (noise, N) combinations:
        Nm Sm - (monotisch, m) signal and noise only to a headphone.
        N0 Sm - (mixed, dichotisch) signal to one ear; phase noise in both ears.
        Np Sm - (mixed, dichotisch) signal to an ear, noise opposition to both ears, the noise is p Radiant (180 °) to a headphone postponed.
        N0 S0 - (homophasisch, diotisch) signal and noise in-phase two headphones.
        Np Sp - (homophasisch, dichotisch) signal and noise to p Radiant postponed (a headphone is reversed).
        Np S0 - (opposition, dichotisch) signal in phase in both ears; noise Radiant moved to p (noisy opposition).
        N0 Sp - (opposition, dichotisch) signal p Radiant postponed (opposition); noise in phase in both ears.
        Nu S0 - (heterophasig, dichotisch) signal in phase in both ears, noise uncorrelated to the two ears (two independent noise sources).
        Nu Sp - (heterophasig, dichotisch) signal p Radiant postponed (opposition) to both ears, noise uncorrelated to the two ears (two independent noise sources).
  • Note 2: The two ears are identical and the chosen Referenzohr is so determined that the phase difference between 0 and p, or the time difference is positive.
  • Note 3: Interaurale phase differences of the signal and noise are usually between 0 </ = () </ = p, for example, Np / 2 Sp / 2 They are in Subscript for S () and / or N () breaks specified.
  • Note 4: A decimal for the Subscript u between -1.00 <u <+1.00 in the condition NuS () indicates the amount of interauralen correlation of the noise, for example N + .9 Sm The direction of the correlation must always be specified by the sign, with the phase is the same for each ganzzahlen number of Radiants, it should be np / p.
  • Note 5: If a large number of Subscript, so that the sound pressure level difference, in decibels (dB), between the signal and / or noise in one ear, relative to signal and / or noise in the other ear means, such as N20Sm.

(Engl. internalization; internalisation): Eng. Internalization is the perception of a sound, the inside of the head near the head is located. The sound may be the listener through headphones (or similar) be offered, see the head localization.

  • Note 1: It is thought that etc. with headphones performance by the lack of interauralen sound pressure level and phase (time) differences, which are usually caused by head movements, the externalization prevented.
  • Note 2: headphones performance also changed the Außenohrübertragungsfunktion (pinna) significantly, so internalization occurs.

(Engl. interval; interval): The interval between two values x1 and x2 size is a one-dimensional by | x2 - x1 |.

  • Note 1: A interval between two Schällen is defined by its frequency or pitch spacing, depending on the existing context.
  • Note 2: A measure frequency interval [NTG1704], [DIN 13 320] is expressed by the frequency ratio or by the logarithm of the frequency ratio (see cents). Musical pitch distances are usually frequency ratios, ratios between two values x1 and x2 assigned and not the difference.
  • Note 3: in ANSI S3.20-1973 frequency interval is also in the degree of frequency interval.

(Engl. intraaural; Intraaural): The property intraaural word means in the (external) ear arranged [NTG 1704].

Isophone curve

(Engl. isophonic contour; Isophone): A isophone Contour is a curve, which are associated with those sound pressure level and frequency values, in a typical trial defined Abhörbedingungen person under a certain size of a specific cause auditory sensation. The specific sensation, such as loudness, pitch, volume (tonales) or density (tonal) should always be specified (see the same volume curves).



listening event

(Engl. auditory event; hearing event): listening event is the auditory perception object, the oh synonym for the hearing sensation.

listening area, Hörfeld

(Engl. auditory field, auditory sensation area; listening area): The hearing is the surface area of perceived sine tones in a level-frequency chart. It is limited by the absolute hearing and the pain threshold.

listening area

The human ear has an exercise area for sound vibrations, whose frequency between about 16 and 20 000 vibrations per second (Hertz). The listening area also in relation to the sound pressure and a lower limit, called the hearing threshold. The sound pressure (more precisely: Sound Exchange pressure;) corresponds to the pressure of sound waves and is for. I.Lautstärkeempfindung; relevant than ever greater pressure this fails, the more energy is the sound waves. Above the pain threshold is listening event with pain sensations.

The values for the listening area (sound prints) include a scale, which will take place between 0.00002 Pascal (Pa) and 200 of a total of 7 Pa last ten what the amazing power of perception Sinnesorganes ear documented. At the same time, it is clear that one of the absolute sound pressure levels based linear volume scale because of the large margin of the numerical values would be extremely inappropriate.

The hearing threshold (at 2000 hertz) the sound pressure 2.10-5 Pa assigned to what is happening in the dB volume scale the noise level value of 0 dB. At the upper end of the scale, is the pain in sound level value 140 dB, the sound pressure is then 200 Pa.

listening level

(English sensation level listening level;): The hearing level is the sound pressure level in decibels of sound above the hearing threshold of an individual person or group of persons. It is calculated from the difference between the sound pressure level and the hearing threshold of sound.

listening room

(Engl. auditory space; listening room):

  1. The listening room is the physical volume within which Schälle be localized.
  2. The listening room is the set of all places listening event [NTG 1704].

(Engl. lateralization; Lateralisation): Auditorische Lateralisation is the attempt by a person made to determine the direction of a sound appears, left or right of the frontal median level of the head.

  • Note 1: Auditorische Lateralisation is usually limited to Schälle, through headphones or bone line vibrators presented or if Freifeldschälle head movements of the head can be prevented.
  • Note 2: Identical sound stimuli in both ears appear centered on the median level of the head. In dichotischen stimuli with interauralen differences in the period, phase or amplitude shifts the position of appearing against that sound ear, which the earlier arrival time, the leading phase and / or the higher amplitude (see also localization, Binaurales Trading ratio, Präzedenzeffekt) .
  • Note 3: Auditorische Lateralisation is not limited to the head localization.
Level spectrum, spectrum density level

(Engl. spectrum density level, spectrum level; spectrum level): The ........

language audio meters

(English speech audiometer; language audio meters): A language audio meters is an audio meters, which measure either live or recorded voice signals.


(Engl. level; level): The level of size is the logarithm of the ratio of this size to a standard size of the same kind of logarithm base, the reference size and nature of the level must be specified.

  • Note 1: Examples of common species level are the level of electrical power, the squared sound pressure, the voltage squared.
  • Note 2: The level, defined here as he is in units of the logarithm of a reference ratio measured, which is equal to the base of the logarithm.
  • Note 3: In symbols:
L = logr (q/q0)
L = Pegelart determined by the size, is under consideration, measured in units of logrr
r = the base of the logarithm and the reference size
q = size under consideration is
q0 is the same kind of reference
  • Note 4: Differences in the levels of two sizes appropriate q1 and q2 by the same formula, because the rules of logarithms, the reference automatically herausdividiert: logr (q1/q0) - logr (q2/q0) = logr (q1 / Q2).

(Engl. loudness; loudness):

  1. The loudness is the characteristic feature of an auditory sensation in their units sound events (Schälle) on a scale from soft to loud to be classified. The unit of loudness is the Sone.
  2. Loudness is a feeling size, on a scale from quiet to loud scaled. The unit of loudness is the Sone. A sound with a volume of 40 Phon has definition, the loudness Sone 1 [NTG 1704], [DIN 1320].
  • Note 1: loudness depends primarily on the sound pressure of the appeal, but also on the frequency (pitch) and the waveform (spectral composition, tone color) of the appeal.
  • Note 2: the loudness calculated in a stationary Schalles Sone, is following in relation to the volume level in Phon:
ns = 2 (L-40) / 10 where: ns = loudness in Sones L = the volume level in Phons.
The above formula can be approximated by: log10 ns ~ 0.03010 (L - 40)
  • Note 3: the specified relationship defines the value of the Sone (unit of loudness) as a Schalles loudness for the volume level 40 Phon.
  • Note 4: a doubling of loudness represents an increase of Lautstärkepegels by 10 Phon, a halving the loudness equivalent to a decrease in Lautstärkepegels by 10 Phon.
  • Note 5: the above relationship was established in the field from 20 to 120 Phon experimentally confirmed. Outside of this area is to be regarded as extrapolation.
  • Note 6: Lautheitsskala is a relationship between the loudness and the level above the threshold (sensory level, sensation level) of a specific handset. When comparing Lautheitsdaten in Sone and sound pressure level units (dB SPL) or at the averaging of Lautheitsskalen different listeners are the (individual, measured or adopted) thresholds to specify them.
  • Note 7: since Lautheits values by subjective judgments obtained, they may differ depending on the psychophysical testing procedures to apply. The conditions under which Lautheits values collected are always explicit. Specific details and approaches for the calculation of Lautheits values of octave-and-third octave bands (1/3-Oktave) measurements are in ISO recommendation R532 (1966). Methods of calculating the Lautstärkepegels (A, R131, see also 1959).
  • Lautheitsfunktion to S. Stevens.
localization, Auditorische

(English localisation; localization): Auditorische localization is the provision (assignment) of appearing and / or distance of a sound source through a test person.

  • Note: Auditorische localization is primarily by the analysis interauraler phase or time differences in lower frequencies and by the analysis of interauralen sound pressure differences at higher frequencies accomplished. The transitional frequency for the dominance of the two signal parameters is about 1500 Hz

(English localisation; localization): Localization is the recognition of the direction and distance of a real or virtual sound source [NTG 1702].

localization, the head

(Engl. head-in-localisation, location, in the head): When the head localization is listening event at a place within the head perceived see internalization.

localization angle

(Localization angle): Under the localization angle is the angle at which a point source from the main microphone or from a listener appears seen in relation to the main direction [NTG 1702].


masking Kontralaterale

(Engl. contralateral masking; masking, Kontralateral): Kontralaterale masking is masking that arises when the maskierende Schall (Masker) offered an ear, is strong enough to ear at the other one (Maskierungs) evoking effect.

  • Note: Kontralaterale masking is distinguished from Central masking.
Masked threshold Mithörschwelle

(Engl. masked threshold; Masked threshold Mithörschwelle): The masked threshold (Mithörschwelle) of a hearing Schalles is the threshold of a specified Schalles in the presence of another (escaped) Schalles.


(Engl. masking; masking, concealment): There are partial and total masking, simultaneous and temporal, that is forward and backward masking. The sound is maskierende with Maskierer (Masker), with the masked Masked (Maskee).

  1. Under truncation (concealment) is the process whereby the threshold of a hearing Schalles by the presence of another (escaped) Schalles raised.
  2. Masking is the amount by which the hearing threshold of a Schalles by the presence of another (escaped) raised Schalles (Engl. threshold shift). The unit is the common decibels (dB).
  3. Masking, contralateral. See also the central masking
  4. Masking, Monaural. See masking
  5. Masking, backward, Vorverdeckung (Engl. backward masking) describes the condition in which the sound maskierende after masked sound.
  6. Masking, forward, Nachverdeckung (Engl. forward masking) describes the condition in which the sound maskierende before masked sound.
  7. Masking, central (German central masking;) is masking that arises when the masked sound one ear and the sound maskierende the other ear is offered. The village is located on central masking higher in the auditory pathway of the brain.
  • Note: Vorverdeckung (Engl. backward masking), after [Zwicker] understood that the masked sound escaped before.
  • Note: Nachverdeckung (Engl. forward masking), after [Zwicker] understood that the masked the sound escaped.
Maskierungs audio grams

(Engl. masking audiogram; Maskierungs - Audio grams): A Maskierungs audio grams is the graphic representation of the masking noise due to a given. It is used as a function of frequency of the masked sound in decibels drawn.

Mean value

Mean value (Eng: arithmetic mean, average): See mean.

Mechanical shock

(Engl. mechanical shock, shock): A mechanical shock happens when the position of a system in a relatively short time in nichtperiodischer significantly altered. It is characterized by the suddenness and the large displacements and developed significant internal forces in the system.

median, central value

(Engl. median; median): The median divides the distribution of size sound level figures such that one half of the values above and below the second half of the median. The median is a measure of central tendency.

median level

(Engl. median plans; median level): See horizontal plane.

Median level

(English media plane median level;): The median level is a vertical plane, the body in a left and a right divided. It is perpendicular to Frontalebene.


(Engl. mel; Mel):

  1. The Mel is the unity of the pitch. One thousand Mel is the pitch of a 1000 hertz sine Tones (pure tone) with the volume level of 40 Phon. The pitch Schalles an attempt by a person with n times that of the 1000 Mel - sound is judged ntausend Mel, as the pitch is a subjective tone of the times, with a 1 Mel - sound is judged, Mel
  2. The Mel is the unity of the pitch ratio at 40 dB SPL. A sine wave frequency of 125 Hz is the ratio pitch 125 Mel assigned [NTG 1704], [DIN 1304].
  • Note: The 1st Definition refers to: [Stevens, S.S. and J. Volkmann (1940): The relation of pitch to frequency scale: a revised scale. Am.J.Psychol., 1940a, 53,329-353.]
  • Note: Due to the different definitions (1) and (2) there are some significant scale differences.
Migrant waves in the cochlea

(Engl. travelling waves; migrant waves): The migrant high frequency waves breaking very soon after the stirrups; low frequencies running along the basilar and form a maximum vibration near the Apex [BEK]

Mikrobar, Dyne per square centimeter

(Engl. microbar, dyne per square centimeter; Mikrobar, Dyne per square centimeter): This is a Mikrobar acoustics in the unit generally used for printing. A Mikrobar Dyne is equal to one per square centimeter.

  • Note: The term refers to a bar pressure of 10 dyne/cm2. (See also N/m2, Pascal). Average, arithmetically (Engl. mean, mean, arithmetically): The arthmetische mean a distribution of customized figures is equal to the sum of the values divided by the number of values in the distribution. The median value is a measure of central tendency.
  • Note: The algebraic sum of the deviations from the mean of the distribution is equal to zero.
Modal value, mode of statistical

(English mode, statistical; modal value): The modal value of a degree distribution of figures is the value of the most frequently occur. The modal value is a measure of central tendency.


(Engl. modulation modulation) modulation is the variation of the values of a parameter, which characterizes a periodic vibration. Accordingly, amplitude modulation of a vibration sinusoidalen the variation of the amplitude of the oscillation, a frequency modulation sinusoidalen vibration is the variation of the frequency of this vibration, etc.

  • Note: With carrier frequency is the frequency, modulation aufgeprägt, with the modulation frequency spectrum with the modulated.

(Engl. monaural; Monaural): Monaural means the use of only one ear.

Monaurale Diplakusis

(Engl. diplacusis monauralis; Diplakusis monaural): Monaurale Diplakusis is the otologische condition, the sine tones monotisch offered as a multiple tones and / or perceived noise.

Masking Monaurale

(Engl. monaural masking; masking monaural): Monaurale masking refers to the situation where the hearing Maskierer (Masker) and Masked (Maskee) offered the same ear.

Mono table

(Engl. monotic; mono table): mono table refers to the condition of hearing a sound stimulus presented only one ear.

Musical Note

(English musical note; Note): A note (syn. musical score) is a commonly used characters to identify the pitch and / or duration of a sound. The note is also a Tonempfindung itself or the vibration, causing the sensation. The word note is in cases where no symbolic distinction is required, both for the sensation as well as for the physical attraction.

Musical scale

(English musical scale; musical scale): A musical scale is a series of notes (symbols, feelings or stimuli) ordered from high to low in a specified pattern of intervals and for musical purposes.

  • Note 1: A interval between two Schällen is defined by its frequency or pitch spacing, depending on the existing context.
  • Note 2: A measure frequency interval (see NTG1704, DIN 13 320) is expressed by the frequency ratio or dury: Arial; mso-bidi-font-family: "Times New Roman"; mso-ansi-language: EN-US "> Note 3: in ANSI S3.20-1973 is frequency interval) also in terms of frequency measurement interval.
  • Note 4: see Table



Neper (Np) (ger. Neper) is a unit used to express ratios, such as gain, loss, and relative values.

  • The neper is analogous to the decibel, except that the Naperian base e (2.718281828...) is used in computing the ratio in nepers.
  • The value in nepers, Np, is given by Np = ln(x1/x2), where x1 and x2 are the values of interest, and ln is the natural logarithm, i.e., logarithm to the base e.
  • One neper (Np) = 8.686 dB, where 8.686 = 20/(ln 10).
  • One dezibel (dB) = 0.1151 Np, where 0.1151 = ln(10)/20.
  • The neper is often used to express voltage and current ratios, whereas the decibel is usually used to express power ratios.
  • Np is a dimensionless unit (like dB).
  • The ITU recognizes both units.
Next masking

(Engl. forward masking; Forward masking): Forward masking refers to the situation where the hearing maskierende Schall (Masker) before masked (Maskee) occurs.

  • Note: Forward masking is identical to Nachverdeckung (after [Zwicker]), with the sound test (Maskee) after the disturbance Schall (Masker) occurs.

(see also noise, Eng. noise, noise):

  1. Noise is any unwanted sound. In a broader sense is any unwanted noise Disturbanz within a frequency band used as undesirable (electric, acoustic, etc.) waves in a transmission channel or device.
  2. Hearing noise is noise, the silence or a deliberate noise disturbs performance, or hearing sound, one of harassment or ill health leads [NTG 1704], [DIN 1320].
noise risk

(Engl. risk of hearing impairment; noise, hearing risk): The noise risk (risk of hearing damage) is the difference between the percentage of people with hearing problems exposed in a group (noise group) and the percentage of people with hearing impairment in a lärmfreien ( but otherwise equivalent) group.


(Engl. noise; noise): A noise is an irregular, intermittent or statistically random vibration. A noise can continue stable, unstable, or pulse.

When a noise is to DIN 1320 is a sound signal, which usually does not constitute a sound event characterized as Machinery and vehicle noise. From this definition, the random, disorderly nature of noise out because it is Tongemische, composed of many individual sounds together. The noise is therefore an audible signal with a number of frequencies, between which there is no a legal context, as example at the sound of the case. Even when there may be periodic noises operations individual tones emerge, through which a wide band marked noise overlaid share. Such individual tones increase the effect of noise interference and are therefore substantially in the measurement result by a so-called Tonzuschlag.

Noise levels

(Engl. sound power level, sound power level): The noise levels, in decibels, a sound is 10 times the logarithm to the base 10 of the relationship between the power of sound and references performance. The subscription service should explicitly.

  • Note 1: The standard reference sound power is 1 Pico Watt (10-12Watt).
  • Note 2: In the technical acoustics in the USA was the reference performance earlier 10-13Watt

(Engl. noise; noise): Noise is an irregular and intermittent or statistically random oscillation. See also noise.

  • Note 1: When on the nature of noise doubt, an additional designation such as acoustic noise or electrical noise can be used.
  • Note 2: Since the definitions are not mutually exclusive for the distinction is usually the context used.
noise, even inspiring

(Engl. uniform exciting noise; equally exciting noise): Equally inspiring noise will be when the intensity density frequency response is so that each group the same frequency sound intensity deleted [NTG 1704].

  • Note: Because the range of frequency groups with centre frequencies below about 500 Hz frequency, as approximated proportional to the frequency, intensity, the density of the equally inspiring noise up to about 500 Hz and is constantly talked to about 10 dB / decade.
noise, evenly verdeckendes

(Engl. uniform masking noise; evenly verdeckendes noise): Uniform verdeckendes noise will be when this noise disturbance as the sine Mithörschwelle a permanent sound causes the entire listening area of the spectrum is independent [NTG 1704].

Noise, random noise

(Engl. random noise; random noise): random noise is a vibration, whose current size for no time is specified. The current size of random noise can only be achieved through functions of probability distributions specified that for a limited or unlimited time intervals or the size of a sequence of sizes in a given area.

  • Note: A random noise, whose current size of a normal or Gaussian distribution follows is Gaussian random noise.
nominal bandwidth

See bandwidth



(Engl. octave; octave):

  1. one octave is the interval between 2 Schällen which is the fundamental frequency ratio 2: 1.
  2. one octave pitch is the interval between two tones in which a doubling of perceived pitch.
  • Note 1: The interval in octaves between two frequencies is expressed in units of the logarithm to the base 2 (or 3,322 times the logarithm to the base 10) of the frequency relationship.
  • Note 2: The frequency ratio, an octave interval to assess the pitch, is close but not always exactly 2: 1


partial sound

(Ger. Teilton):

  1. A partial sound is a physical component of a complex sound.
  2. A partial sound is a component of a sound sensation that can be distinguished as a pure sound, not from the ear can be analyzed and the timbre of the complex tone.
  • Note: The frequency of a sound part may be higher or lower than the fundamental frequency (base rate) and may, but need not integer multiple or a Submultipel the fundamental frequency. If the rate is not a multiple or Submultipel is the partial sound is not harmonic.
perception categories

(Engl. categorical perception, perception categories): perception, designated categories. Z.B. in the western music are intervals in the range of 2.5 to 3.5 semitones as small thirds.


(Engl. period; period): The period of a periodic size is the smallest increment of an independent variable in which the function itself repeatedly.

  • Note: An example of a pure periodic wave is the sine wave or a strictly harmonious sound.
performance, sound

(Engl. sound power; sound power): See sound performance.


(Engl. pitch, pitch): The pitch is the property of a auditory sensation that Schälle on a scale that can be classified, which extends from deep to high. (The unit of the pitch is Mel)

  • Note 1: The pitch depends primarily on the frequency of the Schallreizes, but also by sound pressure and the waveform of the appeal.
  • Note 2: The Schalles a pitch can be described by the frequency or the frequency level of a pure sound (sine tone) with a certain sound pressure level of the test subjects in the same vertical pitch will be measured.
Polar pattern

(Engl. directivity; polar pattern): The polar pattern of a microphone (or speaker) at a certain frequency, with the direction factor or index described in the main from the ratio of output in a horizontal plane sideways received signal to the output to a directly in front incident signal. The direction factor for the frequency f is calculated as follows:

DI = 10 log10Q (f)
where f (Q) = E (Q) / E (0), the ratio of the RMS output of the microphone at the angle of incidence Q and the RMS output at Q = 0
  • Note: The direction index is the direction factor expressed in dB.
power density spectrum

(Engl. power spectral density; sound power density): The power density spectrum of a function X (t) is defined by the transformation:

where R (t) the autocorrelation function of X (t). S (w) is proportional to the medium density squared spectrum W (f) as follows:
  • Note 1: The factor 4p arises from the difference in frequency units 2p and the fact that both positive and negative frequencies for S (w) are allowed, resulting in a straight role.
  • Note 2: the power density spectrum is in the field of random vibrations for each class of physical parameters including displacement, velocity, pressure and acceleration used.

(Engl. psychoacoustics; Psychoacoustic): The psycho-acoustics is the science that deal with the psychological Korrelaten the physical parameters of acoustics. The psycho-acoustics is a part of psychophysics. The psycho-acoustics is a part of psychophysics. It is the science that deal with the psychological Korrelaten the physical parameters of the acoustics, also of sound, and its production, transfer and its effects, employs (ANSI S3.20-1973). The psycho-acoustics investigates the physical effects of acoustic signals to the conscious experience and trying to mutual relations mathematically.


(Engl. psychometry; psychometrics): The psychometrics include measuring psychological processes through the application of mathematical and statistical techniques.

Psychometric function

(Engl. psychometric function; Psychometric function): a psychometric function is a mathematical relationship in the independent variable is some attraction unity and the dependent variable is a response unit.

  • Note 1: A psychometric function is usually described by a graph in which the stimulus dimension on the abscissa (X-axis) and the response dimension to the ordinate (Y-axis) is applied. Graphic depictions psychometric functions as a psychometric curves.
  • Note 2: Examples of psycho-physical functions are the [Weber Fechner] Act or the law of power [Stevens].

(Engl. psychology; psychology): The psychology is the science which the deliberate processes and states with their causes and effects, and their role in the development of personality to investigate (Rohracher, 1971, p.4;). The psychology is especially the science of behaviour, including the study of motivation, learning, perception, etc. (ANSI S3.20-1973).



Reverberation (ger. Nachhall) is all sound due to reflexions measured in a closed system (room) after the sound source has stopped activity.

reverberation time

The reverberation time (ger. Nachhallzeit) is defined as the time needed the sound level reaches -60dB of average active sound level after stopping the sound source.


(see animation created by Tom Henderson of Glenbrook South High School.): 1 inversion at one end; 2 is not inverted, free end, 3 at a boundary in the medium (less dense - thick)

Reflection-free chamber

(Syn reflection-free space, free-field area;): See sound dead space

Reflection-free Zone

(Engl. anechoic room; reflection-free Zone): A reflexionsfreier room is equipped with space limitations, almost the entire they object to absorb sound, making the effect, open-field conditions.

  • Note 1: A sound dead space is an area in which unusually high Schallarbsorption prevails.
  • Note 2: It is assumed that sound spaces against environmental noise particularly well shielded.
Resolution Stereophonische

(Stereophonische resolution): stereophonischer resolution is meant to improve transparency by the localization of sound sources part [NTG 1702].


(Engl. Resonance): See Figure


(Engl. response; Response): The response of a system or a system is the output as a result of agitation (stimulus) under specified conditions.

  • Note 1: For more descriptive remarks must Response bevorgehen the term to indicate what kind of input or output is used.
  • Note 2: The response characteristics, often graphically, the response in relation to any independent variable, such as Frequency or direction. For such applications, it is economically reasonable to assume that other input characteristics (such as voltage) constant.

The Richtungsdiffusität is a measure of the direction depending on the intensity in the diffuse sound field [see Thiele, Acustica 3, 1953] [NTG 1702].

direction information

(Engl. directivity information; directional information): The direction is the information in a sound field or in a stereo transmission direction contained characteristics.

Backward masking

(Engl. backward masking; backward masking): backward masking means the hearing with the condition maskierende Schall (Masker) after the masked Schall (Maskee) occurs (see masking, backward;).

  • Note: Reverse is the same as masking Vorverdeckung, with the sound test (Maskee) before the noise disturbance (Masker) occurs.



(Engl. loudspeaker; speaker): A speaker is an electro converters for the purpose of radiation acoustic performance in the air, while the acoustic wave is essentially equivalent to electrical input.


(English sensation; sensation): sensation is an element of the response from the influencing a stimulus to a sensory receptor results.

  • Note: A sensation size is the name of not unterteilbare elements (elements) of sensation on separately to be respected [NTG 1704]
Sensory level, above the threshold level

(English sensation level (SL); level above threshold; sensory level): The level of a sensation Schalles is always the sound pressure level in dB above the hearing threshold test of a single person or a specified group of test subjects.

speech transmission index

Speech transmission index (ger. Sprachverständlichkeit) is a number between 0 an 1 representing the normal human ability to understand the contents of a spoken message based on sound properties. 0 represents a bad STI, 1 represents best STI. Derivates of the STI are RASTI (rapid speech transmission index) and STIPA (STI public address - a spezialized selection of representative data for public address applications).


(Engl. complex tone, sound, sound): syn Complex clay.

  1. Under sound is an audible sound wave, the simple sinusoidale components with different frequency and amplitude usually contains different (sound: complex tone).
  2. A complex sound is a sound sensation caused by more than one pitch is characterized.
  3. Under sound is a listening sound of several shades of [NTG 1704], [DIN 1320].
  4. Harmonic sound (Engl. complex harmonic tone; harmonic sound). Harmonic sounds are nichtsinusförmige, periodic sound waves, the simple additive from different tones (sine tones, harmonic) with the frequencies 1f1, 2f1, ... , (N-1) f1, nf1, which are integral to each other in a relationship, assembled.
  • Note: sounds can typically more than one pitch causing sensation. They are supported by their frequency spectrum.

(English sound; sound):

  1. Vibration of pressure, density, particle shift speed of the particles, etc. in a medium with internal forces (for example, elastic or viscous), or the storage of such spreading vibrations.
  2. An auditory sensation caused by vibrations as described above.
  • Note 1: Not all sound waves call an auditory sensation; eg Ultrasound or surface waves.
  • Note 2: the medium in which sound, there is often caused by an adjective means, such as Air, water or sound body.
sound absorption

(Engl. sound absorption; sound absorption): Sound absorption is the conversion of sound energy in a different energy, usually heat (dissipation), while a medium or through a porous surface hindurchgeht.

  • Note 1: The sound absorption area is the ratio of nichtreflektierten sound energy to the total incident sound energy for a given frequency, under specific conditions. Unless otherwise indicated, a universally uniform (diffuse) sound field.
  • Note 2: The sound reflectance an area is the ratio of the reflected sound energy to the total incident sound energy for a given frequency, under specific conditions. Unless otherwise indicated, a universally uniform (diffuse) sound field.
sound absorption

The space created in a sound propagates as a wave of airborne sound and space limitation applies to land which was partly the sound and absorb z.T. reflect. Carpets are the only flooring, which adequate sound absorption airborne noise. In the acoustic calculation for the carpeting the required sound absorption. The measurement is done in a reverberation room by comparing the reverberation times with and without plate. The bauphysikalische test is carried out according to DIN 52 212nd --> Sound insulation.


(Engl. sound insulation, soundproofing): ... by partition walls ....


(Engl. sound absorption; soundproofing): e.g. Friction see sound absorption.

sound pressure

(Engl. sound pressure; sound pressure): The sound pressure at a point, the entire current pressure at this point in the presence of sound waves, minus the static pressure at this point.

sound pressure, effective

(Engl. sound pressure effective, root-mean-square sound pressure; sound pressure more effectively): The effective sound pressure on a point is equal to the square root of the current sound pressure over a time interval at which point are under observation. For periodic sound pressure must be the interval a whole number of periods or an interval, in comparison to the long term. For nichtperiodische sound pressures, the interval should be long enough so that the particular value of small changes in the length of the interval independently.

  • Note: The term effective sound pressure is often abbreviated to sound pressure.

(Engl. Sound Pressure Level; SPL): The sound pressure level in decibels, a sound is 20 times the logarithm to the base 10 of the relationship between the pressure of this sound to a reference pressure. The reference pressure must be explicitly stated.

  • Note 1: The standard reference pressure is a) 20 micro-Newtons per square meter (2.10-5N/m2) for sound in gases and b) 1 micro-Newtons per square meter (10-6N/m2) for sound in liquids. The reference pressure a) is in common use for measurements in the field of hearing and sound in the air and liquids; b) has been widely accepted for the calibration of Übertragern and for different measurements of sound in liquids.
  • Note 2: Unless otherwise indicated is the sound pressure the effective (root-mean-square, RMS) sound pressure.
  • Note 3: It should be noted that in many fields, the sound pressure are not with the square root of the power relationships are equal.
  • Note 4: The sound pressure level is approximately equal to the sound power level minus 10 times the logarithm to the base 10 of the plane through the whole sound power hindurchgeht if the area is expressed in square feet.
0 -10 dB = beginning of the hearing range
= 20 dB noise leaves Leises
30 dB = Gedämpfte residential noise
40 dB = Average residential noise
50 dB = usual entertainment, radio room volume
60 dB = Speak Loud
65 dB = beginning of the vegetative damage to the nervous system
70 dB = typewriter, Fernsprechklingel
= 80 dB, rich in road transport
= 90 dB volume factory hall
100 dB = Bosch horn, motorcycle noise
120 dB = pain threshold
Definition of sound:
10 lg = Lp (p12 / p02) (dB) = 20 lg (p / p0) (dB)
Lp = SPL
p = sound pressure (at this level value)
p0 = reference sound pressure
(normalized hearing threshold = 2 x 10-5 Pa)
sound pressure level spectrum

(Engl. spectrum sound pressure level; spectrum of sound pressure level): See spectrum level.


(Engl. sound emission): From a sound source ausgesandter Schall (emission). The term is used in legal provisions.

sound energy

(Engl. sound energy; Sound Energy): The sound energy of a given part of a medium is the total energy in this part of the medium minus the energy, in the same part of the medium is contained if no sound waves are present.

sound energy density

(English sound-energy density; sound energy density): The sound energy density at a point of the sound box is the sound energy, in a infinitesimalen part of the media included, divided by the volume of this part of the media.

  • Note 1: The current terms of energy density (Engl. instantaneous energy density), maximum energy density (Engl. maximum energy density) and high-energy density (Engl. peak energy density) have similar meanings to the relevant terms that for the sound pressure are used .
  • Note 2: If the average energy density (Engl. average energy density) is spoken, it is generally necessary space between the average (at a given time) and one-time average (at a given location point).
  • Note 3: In a plane wave, at a point of a field with standing waves, the sound energy density averaged in space, on the Ausschlages distance of the longest wavelength: where:
xx = the ratio for specific gases for heating = 1.4 for air and other gases diatomische
Patm = barometric pressure.
sound energy flow

(English sound-energy flux; sound energy flow): The sound energy flow is the average rate of flow of sound energy for a period specified by any surface.

  • Note: In a medium with the density r, for a flat or spherical wave with the free propagation speed c, the sound energy flow through the area S, in accordance with an effective sound pressure p:
Where: Q = the angle between the propagation of sound and direction of the standards to the area p.
Sound energy flux density

(English sound-energy flux density; sound energy flux density): syn sound intensity.

sound energy flux density level

(Sound energy flux density level): syn sound intensity level.

sound field

(Engl. filed sound, sound field): A sound field is an area of the sound waves.

sound field, free

(Engl. free sound filed; free sound field): A sound field is an area where only free progressive sound waves.

sound field, diffuse

(Engl. diffuse sound filed; Diff Uses sound field): A diffuse sound field is a sound field in which the average time the APR (RMS) sound pressure is the same everywhere and the flow of energy in all directions equally likely.

speed of sound

(Engl. speed of sound; speed of sound): The speed of sound (including reproductive speed, propagation speed of the wave state) is the speed with which a sound wave travels through a medium (see speed, speed).

5m = 14.6ms
10m = 29.2ms
15m = 43.8ms
20m = 58.5ms
25m = 73.1ms
30m = 87.7ms
35m = 102.3ms
40m = 117.0ms
45m = 131.6ms
50m = 146.2ms
60m = 175.4ms
70m = 204.7ms
80m = 233.9ms
90m = 263.2ms
sound immission

(Engl. sound immission): From a sound source ausgesandter and at a measuring point identified Schall (immission). The term is used in legal provisions.

Sound intensity

(Engl. intensity sound, sound-energy flux density, sound-power density; sound intensity): The sound intensity in a specified direction at a point, the average rate of sound energy, in the specified direction, by a single area, normal for this Direction to the point of consideration is transferred.

  • Note 1: The sound intensity in any specified direction of a sound box is the sound energy flow through a single area to normal this direction. This is given by the expression:
where: T = a whole number of periods or a time interval, the long term compared to
p = the current sound pressure
va = component of the current speed particles in the direction of a
t = time.
  • Note 2: In the case of a free plane wave or a ball wave, the effective sound pressure, the propagation speed c, in a medium with the density r, is the intensity in the direction of the spread given by:
sound intensity level

(Engl. sound intensity level; sound intensity level): The sound intensity level, in decibels, a sound is 10 times the logarithm to the base 10 of the relationship between this sound and the reference intensity. The reference intensity should be explicitly mentioned.

  • Note 1: The standard reference sound intensity is 1 Pico watts per square meter (10-12 watts / m2).
  • Note 2: In a free plane wave fortscheitenden ball or wave is a known relationship between sound intensity and pressure, so the sound intensity level in the measurement of sound can be derived. In general, however, there is no simple relationship between the two and a measurement of sound should not be equated to the sound intensity level.
Sound power, a sound power source

(Engl. power of a sound source; sound power): The sound of a power source is the total sound energy per unit of time transmitted from the source.

Sound power density

(Engl. sound power density; sound power density): syn sound intensity

Schalleistungs-range level,

(Engl. power spectrum sound level; Schalleistungs spectrum level): See spectrum level.

Schalleistungs spectrum density

(Engl. sound power spectrum density; Schalleistungs spectrum density): See performance spectrum density.

sound level

(Engl. sound level; sound level): The sound level is a weighted sound pressure level, through the application of certain Meßcharakteristika and weightings, A, B, C or D. The weightings A, B and C are specified inUSA Standard Specification for General Purpose Sound Level Meter, S1.4-1961, in Europe: xxxxxxxxxx ????. The D-weighting, formerly known as N-weighting is primarily used for the measurement of jet aircraft noise. The weighting applied must always be given. The reference pressure is 20 micro-Newtons per square meter (2.10-5N/m2 or 2.10-5 Pascal) for measurements in air.

  • Note 1: A common method of weighting is indicated for example: the C-noise level was 85 dB or the sound level was 85 dB (C).
  • Note 2: The absolute sound pressure rises at 10-fold when the sound level increases by 20 dB. A sound pressure 1:2 ratio represents the difference in sound level 6 dB. The sound power (in watts) and the sound intensity (W/m2) tenfold in steps of 10 dB. A performance ratio 1:2 corresponds to the difference in sound level 3 dB.
  • Note 3: For questions of sound protection is the important fact that the people of Lautheitsempfindung also follows a power function, according to a factor of 10 higher sound power or a noise level increase of 10 dB than doubling the perceived loudness. This is referred to as "loudness" the size of the subjective assessment volume (expressed in "sone").
Sound level meter

(Engl. sound level meter; sound level meter): The sound level meter is a device consisting of a microphone, an amplifier, a display instrument and frequenzbewertenden circuits for the measurement of noise and noise in specified ways.

  • Note: Specifications for sound level meters are given in U.S. Standard Specification for General Purpose Sound Level Meter, S1.4-1961, in Europe: xxxxxxxxxx ????.

(Engl. sound perimetry; Schallperimetrie): Schallperimetrie is to measure the auditory area of a person (see also: auditorischer space, auditory space).

Sound sample

(Engl. sound probe; sound sample): A sound sample is a device which is sensitive to a property of a acoustic wave (such as sound pressure, sound Fast) and to measure these characteristics in a sound field that can be used without the sound field to change significantly.

Sound shadow

(Engl. sound shadow; sound shadow): A shadow is the sound in a sound field, because of his contact with an obstacle, in relation to the open field values in the size is reduced.

  • Note 1: The reduction in the size of the sound field can be made on the basis of reflection, refraction, absorption and dispersion of sound field through the obstacle.
  • Note 2: The sound shadow of the auricle and / or produced by the head supports the localization of Schällen of about 1500 Hz or more.

(Engl. sound spectrograph; Schallspektrograph): A Schallspektrograph is a device with which the amplitude frequency distribution of a noise as a function of time can be displayed.

Sound radiation pressure, sound radiation

(Engl. radiation pressure, acoustic; sound radiation pressure): The sound radiation pressure is a unidirectional stationary pressure on a surface effect, the sound waves is exposed.

Sound wave

(Engl. sound wave; sound wave): See shaft; tuning fork.


(Engl. beats; Schwebungen): Schwebungen are periodic variations resulting from the superposition of two simple harmonic size (slightly) different frequency f1 and f2 (and similar high amplitude). Schwebungen have the periodic purchase and Abschwellen the amplitude in the Schwebungsfrequenz (Engl. beat frequency;). (f2-f1) result (see also interference).

Subsonic frequency

(Engl. infrasonic frequency, subsonic frequency; subsonic frequency): A subsonic frequency is a frequency, below the audio frequency range.


(English simultaneous masking; Simultanmaskierung): Simultanmaskierung means the hearing condition with maskierender Schall (Masker) and Masked Schall (Maskee) at the same time erklingen (see masking, simultaneous).

Sense Quantum

(Engl. sensory quantum; sense Quantum): If the appeal is continuously increasing the neural response in discrete jumps (quantum). [By Békésy (1964 a, b)], [Stevens & Volkman (1941)].

Sine wave, pure

(simple) Tone (Engl. pure tone, simple tone; sine wave):

  1. A pure tone is a sound wave whose instantaneous sound pressure sinusoidalen a simple function of the time follows (sine wave).
  2. A pure tone is a sound sensation, whose uniqueness is characterized their pitch.
  • Note: Whether a person makes a sound attempt as a pure tone or complex hears depends on their ability, experience and listening habits (see complex sound, sound).

(Engl. Sone; Sone): The Sone is the unit of loudness. By definition creates a sine wave with the frequency of 1000 Hz, 40 dB above the threshold of the listener, a loudness of 1 Sone. The loudness of any other Schalles, by the handset n times that of the 1-Sone sound is judged, Sone.

  • Note 1: A Millisone is equal to 0,001 Sone.
  • Note 2: The Lautheitsskala is a relationship between the loudness and the level above the threshold (sensory level, sensation level) of a specific handset. When comparing Lautheitsdaten in Sone and sound pressure level units (dB SPL) or at the averaging of Lautheitsskalen different listeners are the (individual, measured or adopted) thresholds to specify them.
Spectrum density

(Engl. spectrum density, spectral density; Spektraldichte): The Spektraldichte a vibration is the mean square (mean-square) amplitude of the output of an ideal filter with 1:1 gain, per unit of bandwidth, ie the limit for vanishingly small bandwidth of the ratio of the mean square amplitude divided by the bandwidth.

  • Note 1: In mathematical notation is a vibration Spektraldichte y (t) given by the ensemble average of G (f) and (if a limit exists): where: f = frequency (positive).
  • Note 2: The output of a medium square filter with amplification factor 1:1 in a limited band is given by the integral G (f) related to the frequency of the strip ....?
  • Note 3: Examples of sizes are often used sound pressure, voltage and acceleration.
Spektraldichte level

(Engl. spectrum density level, spectrum level; Spektraldichte level): The Spektraldichte level spezifizlerten a signal at a certain frequency is equal to 10 times the logarithm to the base 10 of Spektraldichte (spectrum density). Generally, the only significant for a signal, which is within view of the frequency range is a continuous distribution of components. The word Spektraldichte level can not by itself be used, it must always be read in conjunction with: for example: pressure, speed, voltage, power.

  • Note: To explain, if desired Lps the Spektralpegel, p the effective pressure by the filtering system is measured, p0 the reference sound pressure, Df the effective bandwidth of the filter system and D0f the reference bandwidth (1 hertz), then
  • Lps = 10 log10 ((p2/Df) / (p02/D0f))
  • For calculation purposes, Lp watched the tape pressure level through the filter, reduces the above equation: Lps = Lp - 10 log10 (Df / D0f)

(Engl. spectrum; spectrum):

  1. The spectrum of a time is a function describing the same in their components, each with a different frequency and (usually) different amplitude and phase (see amplitude spectrum, phase spectrum).
  2. Spectrum is used as a continuous range of components to call, usually with further extension within which certain specified waves have a common characteristic which, z.BAudiofrequenz spectrum.
  3. Continuous spectrum (Engl. continuous spectrum;). A continuous spectrum is the spectrum of a wave, their components continuously over a frequency range distributed. Regardless how small a difference D in the amplitude spectrum specified two Schmalbandfilter specified quotas, whose Diffferenz amplitude of the output is less than D, at any point in the frequency band of the spectrum.
  4. Line spectrum (Engl. line spectrum;). A line spectrum of the spectrum is a wave whose components in a number of discrete frequencies representation.
  • Note: The term spectrum is also in use for other functions of variables as time and distance.
spherical wave

(Engl. spherical wave; spherical wave): A spherical wave is a wave at the wave fronts concentric spheres (see spherical wave).

Peak level

(Engl. peak level; peak level): The peak level is the maximum current level, within a certain specified time interval occurs. In the acoustics of which is normally the peak sound pressure level, except for a different type of level is clearly indicated.

intelligibility, articulation

(English articulation, intelligibility; intelligibility): The percentage of intelligibility of a communication system is given by the percentage of correct reproducible language units, either by one or more speakers are spoken and one or more listeners down, checked or repeated. The word articulation is used when the language material from senseless syllables and fragments together; clarity is needed when it comes to complete meaningful words, compound words, sentences or paragraphs.

  • Note 1: It is important the type of material and language to specify the units in which the material for the purpose of calculating the percentage analysed these units can be: basic language sounds, syllables, words, phrases, etc.
  • Note 2: The percentage of articulation or intelligibility is a property of the entire communication system: Speaker, transmission equipment or medium, and listeners. Even if to draw attention to a component of the system is laid (such as a speaker, a radio receiver), the other system components specified.
  • Note 3: The type of language material is used by a corresponding property description specified: Expressions like syllable intelligibility, single-volume articulation, vowel articulation, Konsonantartikulation, Einsilber word intelligibility, single word comprehension, are the individual records in use.
strength of a sound source

(Engl. strength of a simple sound source; strength of a sound source):

  1. The strength of a simple sound source is the current maximum rate of Volumsverlagerung, by the source is produced when a shaft with sinusiodaler variation over time aussendet. The unit is volume per second.
  2. The strength of a simple sound source is the RMS size of the rate of Volumsverlagerung, produced by the source if it is a shaft with sinusoidaler Varation over time aussendet.
  • Note 1: (1) or (2) in use should always be specified.
  • Note 2: A simple (simple) sound source is a sound source whose dimensions are small in relation to the wavelength. [Misc. Def]
Standard deviation

(English standard deviation; standard deviation): The standard deviation of a distribution of indicators is the square root of the variance. The variance is the difference between the average squares of values and the square of the average value of distribution. The standard deviation is a measure of variability.

static pressure

(Engl. static pressure, static pressure): The static pressure at a point in the print medium is, at this point would exist if no sound waves. In normal barometrischem PO pressure is approximately equal to 101 kNewton/m2 (10 dynes/cm2). This represents a barometer is 0,751 m (29.6 in.) Hg (mercury) when the temperature of the mercury 0 ° C.

  • Note: in English. Normal conditions) is a Q temperature of 0 ° C and a gas pressure of PO of 760 Torr.

(Engl. stereophony; stereo): Under stereophony is (electro) systems, recording and playback conditions, which with the help of 2 or more microphones, speakers channels and a spatial distribution of sound sources during playback is achieved.

Stereophony, intensity

(Engl. intensity stereophony; Intensitätssterophonie): Under Intensitätsstereophonie is stereophone systems, recording and playback conditions, which with the help of 2 or more microphones, 2 channels and speakers in the strict avoidance of time differences between the channels, a spatial distribution of sound sources during playback is achieved.

  • Note 1: The avoidance of time differences between the channels by broadcasters for reasons of Monokompatiblität.
  • Note 2: Under natural conditions are hearing, except for special cases, the spatial Listening (localization of sound sources) always interaurale time and intensity differences interaurale effective.

In the stereo microphone are aufnahmeseitig following orders or recording systems usual:

  1. XY system: A XY system is a two-channel system with two in a reception point united Richtmikrophonen whose Achsrichtungen symmetrical to the connecting line of the receiving point with the focus of the event are sound [NTG 1702].
  2. MS System: An MS system is a two-channel system with two in a reception point Richtmikrophonen united, one of which (M) with its main axis in the focus of the sound event is addressed, while the main axis of the second, as a recipient gradient (S) switched microphone ( Pressure differential microphone) is perpendicular to [NTG 1702].
  3. AB system: An AB system is a two-channel system in which two similar microphones in a cross set apart [NTG 1702].
  4. Coincidence microphone (Engl. coincidence microphone). Under a coincidence microphone sees two microphone systems in kleinstmöglichem distance, time differences run so not to be effective (for example, in the intensity stereophony used) [NTG 1702].
  • Note 1: recording and playback base is the distance between the outer microphones in an AB system, or the distance between the speakers.
  • Note 2: recording and playback distance is the distance between the sound source from the line of microphones (recording base) and the removal of the earpiece of the line of the speaker (play basis).
Stereophony, Kopfbezogene

(Engl. head related stereophony; Kopfbezogene stereo): Under Kopfbezogener stereo is a two-channel transmission, preferably by using an artificial head. See Kunstkopfstereophonie, binaural stereo [NTG 1702].

stereophony, runtime

(Laufzeitstereophonie): Under Laufzeitstereophonie is a multi-channel transmission, mainly in the run-time differences for the formation of the stereo effects are relevant [NTG 1702].

stereophony, Spatial

(Spatial stereo): Under Raumbezogener stereo is a multi-channel transmission with speakers playing [NTG 1702].

stereophony, pseudo -

(Engl. pseudo-stereophony; Pseudostereophonie): With Pseudostereophonie refers to a sound transmission with einkanaliger multichannel recording and playback with the apparent aim of increasing the sound source [NTG 1702]. Knüppelstereophonie is a Pseudostereophonie in the direction of information regardless of the original sound image is entered by hand. Trickstereophonie is a Pseudostereophonie in the direction of information through a control signal is transmitted.


(Engl. subharmonic; Subharmonic): A Subharmonic is a sinusoidale size with a frequency that an integer Submultiple of the fundamental frequency of the periodic size, to which they (the Subharmonic) in relation.


(Engl. summation tone; Summationston): A Summationston is a combination sound with a frequency that is equal to the sum of the frequencies of two primary tones or its harmonics (see combination tone).


(Engl. velocity, speed): Speed is a vector of temporal change of the geographic location of a particle in relation to a specified reference point. The amount of the vector is derived from the ratio of the previous path (Wegabschnitt) of a particle (linear movement) and the necessary time (period).

(changing the place) / (change of time) = (later position - former position) / ? t
v = (f (t + ? t) - f (t)) / (? t) is the average speed.

If the amount of the time constant speed (average), is the movement as a uniform. For a description of the instantaneous velocity (speed moment) a ungleichförmigen movement is the average speed to increasingly smaller time interval. If you go after 0 Delta, obtains:

v = lim (? t to 0) (f (t ? t) - f (t)) / (? t)
  • Note: If the reference point trägheitslos, the speed often called the relative speed.
speed level

(Engl. velocity level; speed level): The speed level (in decibels) of a sound is 20 times the logarithm to the base 10 of the ratio of particles speed of sound to a reference-speed particles. The reference particles speed must be explicitly.



(Engl. threshold; threshold): Under a psychoacoustic threshold is generally an acoustic stimulus with specific expression in a stimulus size, because of the sensibility (Engl. sensitivity;) of the subject to a change in responsiveness. There are thresholds and absolute difference thresholds. The absolute hearing threshold is the lower limit of the sensory assets of hearing (at 1000 Hz about 2.10-5N/m2).

Threshold Feel

(Engl. threshold of feeling, of tickle; Fühlschwelle): The Fühlschwelle for a specified signal is the minimum sound pressure level at the entrance to the Ohrkanals, in a specified share of the ear attempts up to that point stimulated, in which a Fühlempfindung, with different from the listening feeling that occurs.

Threshold, pain -

(Engl. threshold of pain, pain threshold): The pain threshold for a specified signal is the minimum sound pressure level at the entrance to the Ohrkanals, in a specified proportion of experiments, the ear up to that point stimulated, in which a sensation of pain, different from the nichtverletzenden hearing and Fühlempfindung is occurring.

Threshold difference

(Engl. differential threshold; difference threshold): The difference threshold or Limen difference is the minimal change (the limit) a stimulus, in a specified proportion of trials a correct assessment of the difference to a reference stimulus causes.

  • Note: Instead of the method of constant stimuli (Constance method), by the English wording. a specified proportion of experiments) implies, may psychophysical another method (which should be specified).

(Engl. timbre; tone):

  1. Timbre is the property of a auditory sensation that a listener two in the same way Samaritans Schälle the same loudness and pitch the same cause as a different judge.
  2. Timbre is next pitch, volume and other properties, a characteristic of the hearing sensation, which is multidimensional on different scales can express, for example bright-dark or sharp-dull, etc. The tone is essentially through the course of the spectrum determined [NTG 1704].
  • Note: the timbre depends primarily from the spectrum of the stimulus, but also by the wave form, the sound pressure, the situation in the spectrum of frequencies and the temporal characteristics of the stimulus (A).
the same volume curves

(Engl. equal loudness contour; curves same volume): A curve equivalent (constant) Volume (syn volume contour; loudness contour; loudness level contour) those assigned to each other SPL and frequency values, which in a typical experimental person under a certain defined Abhörbedingungen Volume sensation (loudness) cause.

  • Note: The same volume curves were originally intended for sinus tones, but also for other spirit narrowband signals.
throttling, partial masking

(Engl. partial masking; throttling): Under throttling (partial concealment) is the reduction in loudness of a sound by the presence of other Schälle.


(Engl. transparency, transparency): transparency is at Musikdarbeitungen the distinctness of temporary successive sounds and noises and simultaneously erklingende instruments and voices.


(Ger. Ton): see also sound.


(Engl. tonal; Tonal): syn. pure tone.

Tonale density

(Engl. tonal density; Tonale density):

  1. The density (tonal) is the property of a auditory sensation that a sound on a scale of compact diffuse to be classified.
  • Note: The increasing density of a tone both with the intensity as well as with the frequency and then appear higher tones compact (have a greater density) than low.
Tonales volume

(Engl. tonal volume; Tonales volume): The volume (tonal) is the property of a auditory sensation that a sound on a scale of geographically close and geographically can be classified.

  • Note: The volume of a sound increases with the intensity, however, takes off with the frequency and then appear higher tones geographically close (have less volume) as low.

(English tonality, tonal; tonality): tonality, syn. Chroma sound is the phenomenon that sounds, one octave apart in the pitch perceived to be closer than any other interval (see chroma).

  • Note: tonality was occasionally as a tonal dimension.


ultrasonic frequency

(Engl. ultrasonic frequency; ultrasonic frequency): An ultrasound frequency is a frequency greater than the audio frequency range. The term is generally used for elastic waves which in gases, liquids and solids reproduce.

  • Note 1: The term ultrasound can be used as a term for equipment or systems used for operations at an ultrasonic frequency are foreseen.
  • Note 2: Supersonic is an old expression for ultrasonic, its use is now being rejected.



(Engl. variance; variance): See scattering, standard deviation.


(Engl. vibration; vibration): vibration is an oscillation whose size is a parameter, the movement of a mechanical system.


(Engl. oscillation; vibration): A variation, usually over time, the amplitude of a size in relation to a specified reference when the amplitude alternately larger and smaller than the reference.

Vibration absorbers, dynamic

(Engl. dynamic vibration absorber, tuned damper; vibration absorber): A dynamic vibration absorber (tuned dampers) is a device to reduce the vibration of a primary system by the transfer of power to an auxiliary response system based on the frequency of vibration vote. The force created by the auxiliary system withdrawn is at the stage opposite to the force in the primary system works.

Vibration, forced

(Engl. forced vibration; Forced Vibration): The vibration of a system is forced, if the response by encouraging imposed. Is the suggestion periodically and continuously, then the vibration is stable.

Vibration, free

(Engl. free vibration; vibration-free): A free vibration of a system is the vibration, without any forced vibration.

Vibration, degrees of freedom

(Engl. degrees of freedom; degrees of freedom): The number of degrees of freedom of a mechanical system is equal to the minimum number of independent generalsierter coordinates, which are necessary for the positions of all parts of the system at any time to be fully defined. In general, is equal to the number of independent generalized displacements, which are possible.

volume level

(Engl. loudness level; volume):

  1. The (judged) volume level of an Schalles in Phon, is numerically equal to the mean sound pressure level in decibels (dB re 2. 10-5 N/m2) of a 1000-hertz tone reference to the test persons in the form of a frontal incident sound wave in a free Sound field and offered them in a certain number of experimental passages (eg 75%) as equal, according to the test shall be assessed.
  2. The (calculated) volume level of a sound, Phon, the loudness in Sones in the following relationship:
L = 40 + 10 ns log2 where: ns = loudness in Sones L = the volume level in Phons.
Accordingly, the (calculated) in loudness Sones: ns = 2 (L-40) / 10
The calculated volume level is the numerical value to identify the strength of a sound that comes out of the Terzpegelspektrum of sound, using non-evaluations (see DIN 45 631) is determined. The volume level is in Phon. For volume Ln 40 Phon following is associated with the loudness n in Sone:
Ln () / (Phon) = 40 + 33.32 lg (s) / (Sone) [NTG 1704], [DIN 45 631].
  • Note: the way an unknown sound to be heard must be determined and can be seen as one of the characteristics of this Schalles be considered.
  • Note: After Lautheitspegel values by subjective judgments obtained, they may differ depending on the psychophysical testing procedures to apply. The conditions under which Lautheitspegel values collected are always explicit. Specific details and approaches for the calculation of Lautheitspegel values are in ISO recommendation R131 (1959). Expressions for the physical and subjective dimensions of sound and noise and ISO recommendation R532. (Methods for calculating the Lautstärkepegels A, R131, see also 1959).
volume speed

(Engl. volume velocity; volume speed): The volume speed is the rate of work-flow of the medium by a specified surface due to a sound wave.

  • Note: In mathematical terms, the volume-speed V: u = component of the particle normal speed element to the surface ie the integration is on the surface S by the medium oscillates.

(Engl. backward masking; Vorverdeckung): syn backward masking.


White Noise

(Engl. white noise, white noise): White noise is a noise which Spektraldichte (spectrum density or spectrum level) substantially independent of the frequency, over a specified area.

  • Note: White Noise does not random noise.

(Engl. wave; wave): A wave is the Disturbanz in a medium such progress that at any point of the medium size, as a measure of Disturbanz serves a function of time, while at any time the deflection at one point a function of the position of the point. Any physical size, the same relationship to an independent variable (usually time), as a progressive Disturbanz, at a certain time, in relation to the place can be called a wave.

Sound waves are Longitudinalwellen

(Engl. wavelength; wavelength): The wavelength of a periodic wave in an isotropic medium is the perpendikulare distance between two wave fronts where the relocation (deflections) a phase difference of a full term.

Wrong alarm

(Engl. false alarm; false alarm): With a false alarm is the one event in a detection situation during a specified interval observation means in which to a "plain noise" stimulus (input) a "signal" response (output). A false alarm, for example, if the response event stimulus event shows even though there is no stimulus was necessary, P (S | n) see also hit, error, correct rejection.



  • [ANSI] American National Standard Psychoacoustical Terminology (1973): ANSI S3.20-1973; Approved December 5, 1973; American National Standard Institute, Inc.
  • [DIN] Deutsches Institut für Normung: Akustik
  • [NTG] Nachrichtentechnische Zeitschrift
  • [PAR] Richard Parncutt (1989): Harmony: A Psychoacoustical Approach; Springer-Verlag Berlin
  • [YOST] Yost, William A. & Donald W. Nielsen (1977): Fundamentals of Hearing. An Introduction. Holt, Rinehart and Winston; New York.