Appendix A LIST OF 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

a	absorption coefficient
e	base of natural logarithms (e = 2.718 ...)
f	frequency
l	wavelength
p	pi = 3.14159265358979 ...
r	reflection coefficient
r	pressure
s	standard deviation
T	period
q	angle
v	velocity
w	angular velocity
Z	acoustic impedance
8va	octave
µ	micro (10-6)

See also Appendix B

---

home