Audio/Acoustics
From eqqon
Contents |
A
- absolute pitch (ger. Absolutes Gehör)
- absolute pitch is the ability to identify the note (frequency) of a clear sine tone without an external reference.
- Note 1: the allowed variance has to be defined.
- Note 2: mostly a note is identified not a frequency value.
- adaptation (ger. Adaptation).
B
- Band power level
- The band power level of a sound for a specific wave band is the sound power level of a sound which passes a limited band.
C
D
E
F
- forward masking (ger. Nachverdeckung)
- see also "masking".
G
H
I
K
L
M
N
- neper (Np) (ger. Neper)
- A unit used to express ratios, such as gain, loss, and relative values.
- Note 1: The neper is analogous to the decibel, except that the Naperian base e (2.718281828...) is used in computing the ratio in nepers.
- Note 2: 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.
- Note 3: One neper (Np) = 8.686 dB, where 8.686 = 20/(ln 10).
- Note 4: One dezibel (dB) = 0.1151 Np, where 0.1151 = ln(10)/20.
- Note 5: The neper is often used to express voltage and current ratios, whereas the decibel is usually used to express power ratios.
- Note 6: Like the dB, the Np is a dimensionless unit.
- Note 7: The ITU recognizes both units.
O
R
- reverberation (ger. Nachhall)
- Reverberation is all sound due to reflexions measured in a closed system (room) after the sound source has stopped activity.
- reverberation time (ger. Nachhallzeit)
- The reverberation time is defined as the time needed the sound level reaches -60dB of average active sound level after stopping the sound source.
S
T
U
V
W
Z
Literaturhinweise
- [ANSI] American National Standard Psychoacoustical Terminology (1973): ANSI S3.20-1973; Approved December 5, 1973; American National Standard Institute, Inc.
- [YOST] Yost, William A. & Donald W. Nielsen (1977): Fundamentals of Hearing. An Introduction. Holt, Rinehart and Winston; New York.