Appendix A: List Abbreviations and Symbols

AC

Alternating Current

ADC

analog-to-digital converter (see Digital Recording)

AI

Articulation Index

AM

Amplitude Modulation

CNEL

Community Noise Equivalent Level

CNR

Composite Noise Rating

cps or c/s

cycles per second (see Frequency)

DAC

digital-to-analog converter (see Sound Synthesis)

DAT

Digital Audio Tape (see Magnetic Tape)

dB

Decibel

dBA

A-weighted decibels (see Sound Level Meter)

dBB

B-weighted decibels

dBC

C-weighted decibels

DC

Direct Current

DSP

Digital Signal Processing or Processor (see Sound Synthesizer)

EPNdB

Effective Perceived Noise decibels

EPNL

Effective Perceived Noise Level

f

forte (see Dynamics)

ff

fortissimo (see Dynamics)

FM

Frequency Modulation

gHz or GHz

Gigahertz

HRTF

head-related transfer function (see Binaural Hearing)

Hz

hertz (see Frequency)

IIC

Impact Insulation Class

IPA

International Phonetic Alphabet (see Vowel)

ips

inches per second (see Magnetic Tape)

ISO

International Standards Organization

jnd

just noticeable difference (see Differential Threshold)

kcps, kc/s, kc

kilocycles per second

kHz

kilohertz (see Frequency)

L

Sound Level (see Noise Level)

M. or M.M.

Maelzel Metronome (see Metronome)

MAF

minimum audible field (see Threshold of Hearing)

mf

mezzo-forte (see Dynamics)

ms

millisecond

NAB

National Association of Broadcasters

NC

Noise Criterion

NEF

Noise Exposure Forecast

NIC

Noise Isolation Class

NIPTS

Noise Induced Permanent Threshold Shift (see Threshold Shift)

NNI

Noise and Number Index

NPL

Noise Pollution Level

NR

Noise Rating

NRC

Noise Reduction Coefficient

NRF

Noise Reduction Factor

OSHA

Occupational Safety and Health Administration or Act (see Damage-Risk Criteria)

p

piano (see Dynamics)

pp

pianissimo (see Dynamics)

PNC

Preferred Noise Criterion (see Noise Criterion)

PNdB

Preceived Noise decibels

PNL

Perceived Noise Level

PPM

peak programme meter (see VU Meter)

PTS

Permanent Threshold Shift (see Threshold Shift)

RIAA

Record Industry Association of America

RMS, rms

Root-Mean-Square

SC

Speech Communication Criterion

SHM

Simple Harmonic Motion

SIL

Speech Interference Level

SNR, S/N

Signal-to-Noise Ratio

SOS

Sound-on-Sound

SPL

Sound Pressure Level

SST

Supersonic Transport

STC

Sound Transmission Class

TL

Transmission Loss

TS

Threshold Shift

TTS

Temporary Threshold Shift (see Threshold Shift)

TNI

Traffic Noise Index

VCA

voltage-controlled amplifier (see Sound Synthesizer)

VCF

voltage-controlled filter (see Sound Synthesizer)

VCO

voltage-controlled oscillator (see Sound Synthesizer)

VU

Volume Unit

WFAE

World Forum for Acoustic Ecology

WSP

World Soundscape Project

Symbols

α

Absorption Coefficient

e

base of natural logarithms (e = 2.718 ...)

f

Frequency

λ

Wavelength

π

pi = 3.14159265358979 ...

r

Reflection Coefficient

ρ

Pressure

σ

standard deviation

T

Period

θ

angle

v

velocity

ω

angular velocity

Z

Acoustic Impedance

8va

Octave

μ

micro (10-6)

See also Appendix B