%ALcons (Articulation Loss; consonants), 393, 404, 415
5.1 surround systems, 367
A
Absolute category-rating (ACR) test, 391
Absorption:
effects on early reflections, 285–286
materials, 339
reverberant sound, 286–295, 297
room mode decay, 322
sound, 44
wideband absorbers, 343, 344, 345
Acoustic bass, 273
Acoustic impedance, 20
Acoustic pressure waveforms, 71, 123, 132, 236
Acoustic spatial filtering, 465–466
Acoustically large rooms, 336
Acoustically small rooms, 336
Active noise cancellation, 416, 417
Adaptive inverse filtering, 422
Adaptive quantization, 428
Adaptive quantizer, 430
Adiabatic gas law equation, 6
Aging, presbycusis, 89
Air absorption, effect of, 321–322
Air columns, see Bores
Air effects, sound, 5–7, 183, 321–322
All-pass filter, 67
Ambience speakers, 367
American National Standards Institute, 131, 232
Amplitude, 20, 23, 34, 92, 93, 191, 193, 234, 348–351
Amplitude reflection gratings, 348–351
Anvil, 76
Aperiodic sound waves, 63–64, 131
Applications, of acoustics and psychoacoustics, 365
audio coding systems, 418
archetypical audio coder, 419–420
entropy coding stage, 424
information, carrying, 420–421
information measurement, 424–425
psychoacoustic noise shaping, 431–432
psychoacoustic quantization, 432–433
psychoacoustic quantization stage, 428
quantization and adaptive quantization, 429–431
signal redundancy removal stage, 421–424
total information measurement, 425–427
critical listening room design, 367
diffuse reflection room, 376–381
energy-time considerations, 369–370
loudspeaker arrangements, 367–368
non-environment rooms, 375–376
reflection-controlled rooms, 370–373
reflection-free zones, absorption level required for, 373
reflection-free zones, absorption position for, 373–375
filtering and equalization, 394
altering the sound balance in mixes, 400–401
correcting frequency response faults, 398–399
timbre modification, of sound sources, 399–400
noise-reducing headphones, 415
psychoacoustic testing, 388
experimental design issues, 389–390
psychoacoustic rating scales, 390–392
speech intelligibility, 392–393
public address systems, 402
good speech intelligibility, requirements for, 407
intelligibility, loudspeaker effect on, 404–405
intelligibility, noise effect on, 405–407
intelligibility, reverberation effect on, 403–404
more than one loudspeaker and delays, 413–415
speech quality measurement, methods for, 415
speaker directivity, achieving, 408–409
pure-tone and speech audiometry, 381–388
Arithmetic Coding, 428
acoustic spatial filtering, 465–466
Articulation index (AI), 415
Artificial reverberation, 321
Audio coding systems, 418
archetypical audio coder, 419–420
entropy coding stage, 424
information, carrying, 420–421
information measurement, 424–425
psychoacoustic noise shaping, 431–432
psychoacoustic quantization, 432–433
psychoacoustic quantization stage, 428
quantization and adaptive quantization, 429–431
signal redundancy removal stage, 421–424
total information measurement, 425–427
Audio compact disc, track listing for, 473–478
Audiogram, 382
Audiometric notch, 103
Auditory nerve, 83
B
Backward adaptive predictor, 423
Backward adaptive quantizers, 430
Backward masking, 263
Band-pass filter, 64, 65, 67, 68
Band-reject filter, 64
Bars
and panels, waves in, 10
bending (flexural) waves, 12–14
quasi-longitudinal waves, 10–11
percussion, 209
Bass drum, 213
Bernoulli effect, 203–204, 217
Binary Amplitude Diffuser, 350, 464
Binaural stereo, 118
“Black Box” model, of musical instruments, 168–169
Blank audiogram, 382
Bone conduction audiometry, 384
Bores (air columns), 198
Boundary effects:
reflection:
bound-unbound boundaries, 46–47
Bounded to unbounded boundaries, sound reflection from, 46–47
Bowed string, sound source from, 176–178
BS EN ISO 8253-1, 383
C
“C” weighting, 95
Capella singing, tuning in, 225–229
CD, see Compact disc
Center dialog speaker, 367
Central cluster, 405
Chiff, 185
Chorus effects, electronic, 245
Circum-aural headphones, 384
Clarinet, 198, 199, 201, 202, 237, 239, 243, 246
Clinical audiometer, 382
Coding, perceptual, 264
Comb filtering, 48
Combination tones, 258
Comma free, 427
Compact disc (CD), 473
Comparison category-rating (CCR) test, 392
Complex Fourier series, 440–441
Complex sounds, loudness of, 99–100
Complex waveforms, 59
Concha, 75
Constant beamwidth theory (CBT) arrays, 467
Constant directivity horns, 408, 467–468
Constructive interference, 48, 50
Contemporary pitch perception, theory of, 146–148
Continuous spectrum, 131
Controlled experimentation, 389
Controlled reflection technique, 371
Convolution theorem, 442–443, 461, 464
Correlated sound sources, 27, 28–30
CQ, see Larynx closed quotient
Critical bands:
consonance and dissonance, 151–153
definition, 74
ERB quadratic equation, 447
Critical bands and timbre, 242–244
Critical frequency, 334–336, 337
Critical listening room design, 367
diffuse reflection room, 376–381
energy-time considerations, 369–370
loudspeaker arrangements, 367–368
non-environment rooms, 375–376
reflection-controlled rooms, 370–373
reflection-free zones, absorption level required for, 373
reflection-free zones, absorption position for, 373–375
Cues and timbre perception, 244–252
Cut-up, adjustment, 184
Cutting/rough tone, 247
Cymbal plates, 211
D
Damping, 352
DBHL, 382
DCC, see Digital compact cassette
Dead room, 299
Decay, 69, 70, 175, 306, 316–317
Degradation category-rating (DCT) test, 391–392
Degradation mean opinion score (DMOS), 391, 392
Delay, 27–28, 114, 116–117, 279, 413
Dependent variable, 392
Design, room acoustics, 367–381
Destructive interference, 48, 50
Deutsch, Diana, 264
DFT, see Discrete Fourier transform
Diagnostic rhyme test (DRT), 393
Difference limen, see Just noticeable difference
Diffuse reflection room, 369, 376–381
Diffuser design, 464
Diffusion materials, 345
amplitude reflection gratings, 348–351
Digital compact cassette (DCC), 264
Direct Stream Transfer (DST), 419
Directivity, reverberant sound, 297–299
Discrete Fourier transform (DFT), 445–446
Displacement antinodes, see Velocity antinodes
Displacement nodes, see Velocity nodes
DMOS, see Degradation mean opinion score
Dolby AC3, 419
Domain representations, 61, 62, 64
Double bass, 81, 131, 170, 180, 267
DRT, see Diagnostic rhyme test
Drum heads, 212
DST, see Direct Stream Transfer
DTS, 419
E
Ear canal insert earphones, 384
Eardrum, 75
Early decay time (EDT), 316–317
absorption effects on, 285–286
and performer support, 318–320
Edgetone, 183
EDT, see Early decay time
Electronic filters, 142
Ellis, Alexander, 248
Enclosed spaces, acoustics of, 279
air absorption, effect of, 321–322
source directivity effects on, 297–299
reverberation time, 299
calculation and prediction, 300–302
variation with frequency, 308–309
standing waves, 322
Enclosure diffraction effects, 358–362
Energy-time considerations, 369–370
Enharmonics, 159
Entropy coding stage, 420, 424
Equal loudness contour, 93, 94
Equal-tempered tuning, 163–165, 175, 206, 225
Equivalent open window area, 310
Equivalent rectangular bandwidth (ERB), 85, 248
ERB equation, solving, 447
ERB, see Equivalent rectangular bandwidth
Errors listeners, 393
Even function, 439
Experimental design issues, 389–390
Exposure times, noise, 104–105
F
f0, see Fundamental frequency
Far-field assumptions, 460
Fan-shaped hall, 317
Filter time responses, 64, 65–68
time and frequency representations, 69–72
time responses, 69
Filtering and equalization, 394
altering the sound balance in mixes, 400–401
correcting frequency response faults, 398–399
timbre modification, of sound sources, 399–400
Filters, 64
band-reject, 64
electronic, 142
equalisation/tone control, 397–398
filter banks, 147
high-pass, 64
Finger holes, 192
Fingering instruments, 193
First order mode, 55
Fletcher–Munson curves, 94
Flexural waves, see Bending waves
Floating room, 354
Flow-controlled valve, 192, 197
Flute, 123, 125, 192, 194, 237, 239, 243
Focusing surfaces, 282
Forward adaptive predictor, 423
Forward adaptive quantizers, 430
Forward masking, 263
complex Fourier series, 440–441
discrete Fourier transform, 445–446
frequency spectrum, 439
odd and even functions, 439
non-periodic signals, frequency analysis of, 441–442
Fourier transform pair, 60, 442
Free field, see Free space
Frequency:
analysis, 81
of non-periodic signals, 441–443
definition, 15
domain representations, 61, 62, 64
interference, 48
and pressure sensitivity ranges, 89–91
proximity grouping, 265
ratios, 128, 129, 159, 163, 164, 449
relative loudness, 94
reverberation time variation, 308–309
see also Critical frequencyFundamental frequencyModal frequencyMode frequency
Frequency domain processing, 423
Fundamental frequency, 122–124
G
Gedackt 8’ ship, 191, 192, 238, 243
Glottal airflow, 218
Glottis, 218
Golf ball and spring model, 3–5
Golomb Rice Codes, 428
Graphic equalizer, 398
Grouping:
by good continuation, 265
by proximity, 265
by similarity, 265
Grouping illusion, notes, 264–270
H
Hammer, 76
Harmonic number, 125
Harmonics:
consonance/dissonance, 151–153
definition, 127
musical notes between, 127–131
square wave, 61
timbre perception, 236, 242, 244
Head, sound localization, 112
noise-reducing headphones, 415–416
Hearing acuity, loss of, 101–102
Hearing sensitivity, loss of, 101
Hearing system:
anatomy, 74
frequency and pressure sensitivity ranges, 89–91
noise-induced hearing loss, 101–104
integrated noise dose, 104–106
sound source direction, perception of, 107
interaural intensity difference, 111–113
interaural time difference, 107–111
pinnae and head movement effects, 111–114
stereophonic listening, 116–119
I
Idiophones, 209
IID, see Interaural intensity difference
Impulse, 208
Independent partitions, 353–354
In-ear monitoring, 319
Input/system/output model, 168, 169, 171, 222
Instruments, see Musical instruments
Integrated noise dose, 104–106
Intensity:
interaural difference, 111–113
Intensity stereo, 117
Interaural intensity difference (IID), 111–113
Interaural time difference (ITD), 107–111
Inter-spike interval histograms, 145, 146
Intervals, musical, 127–131, 153–158
ITD, see Interaural time difference
J
JND, see Just noticeable difference
Just noticeable difference (JND), 137
K
L
Leq measurement, 96
Lab, The, 376
Larynx, 217
Larynx closed quotient (CQ), 218
Leaky bucket model, 291
LEDE, see Live end dead end
LFE, see Low-frequency effects
Linearity and superposition, 461
Lips, embouchure, 194
Live end dead end (LEDE), 370
Localization, sound, 75
Logatom testing, 393
Long-term average spectra (LTAS), 233
Longitudinal wave, 3
Lossless audio coding systems, 418–419
Lossy audio coding systems, 419
Loudness, 231
Loudspeakers, 49, 50, 52, 367–368
Low-frequency effects (LFE), 368
LTAS, see Long-term average spectra
M
Mastoid prominence, 384
Mean opinion score (MOS), 391
Membranophones, 209
Meridian Lossless Packing, 419
Millington-Sette equation, 311, 457
Minimum beamwidth frequency, 470
Mixes, sound balance in, 400–401
Mixture organ stop names, 256
Mixtures, 253
Modal frequency, 322
Modal region, 335
Mode frequency, 199, 200, 209–210, 214, 216
Moderate hearing loss, 386
Modified rhyme test (MRT), 393
MOS, see Mean opinion score
MP3 systems, 264
MRT, see Modified rhyme test
Music hearing, in different environments, 277
absorption materials, 339
wideband absorbers, 343, 344, 345
diffusion materials, 345
amplitude reflection gratings, 348–351
enclosed spaces, acoustics of, 279
air absorption, effect of, 321–322
critical distance calculation, 295–297
early reflections and performer support, 318–320
early reflections, absorption effect on, 285–286
reverberant sound, 286–295, 297–299
reverberation time, 299–304, 308–316
reverberation time equation, 304–305
enclosure diffraction effects, 358–362
loudspeaker output, room boundaries effect on, 356–358
room modes and standing waves, 322
acoustically large rooms, 336
acoustically small rooms, 336
modes, behavior of, 329
universal modal frequency equation, 326–327
sound isolation, 351
independent partitions, 353–354
Musical instruments, 167
fundamental frequency ranges, 169, 170
percussion, 208
speaking and singing voice, 216
sound modifiers, in singing, 219–225
sound source, in singing, 217–219
tuning in capella singing, 225–229
stringed, 170
bowed string, sound source from, 176–178
plucked string, sound source from, 172–173
struck string, sound source from, 173–176
wind, 181
woodwind flue instruments, 192–194
woodwind reed instruments, 197–202
Musical intervals, 127–131, 153–158
Musical tones, 247
acoustic pressure waveforms, 122, 123, 124–125
fundamental frequency, 122–124
hearing, 150
consonance and dissonance, 151–153
harmonics and development of Western harmony, 150–151
N
Nasal harmonics, 243
National Physical Laboratory (NPL), 417
Nicking, flue organ pipes, 184–185
Noise-induced hearing loss, 101–104
integrated noise dose, 104–106
Noise-reducing headphones, 415–417
Non-environment rooms, 369, 375–376
Non-harmonic sounds, 136
Non-linear quantization, see Non-uniform quantization
Non-periodic signals, frequency analysis of, 441–442
Non-periodic sound waves, spectrum of, 63–64
Non-simultaneous masking, 263
Non-uniform quantization, 431
Norris–Eyring reverberation formula, 301, 304–305, 310, 453
Norris–Eyring reverberation time equation, 456, 457
Notch Filters, 394
Note grouping illusions, 264–270
Note offset phase, 236
Note onset phase, 236, 237–242
NPL, see National Physical Laboratory
O
On the Sensations of Tone, 247
Odd function, 439
Ohm’s second (acoustical) law, 135
Organ flue pipes:
Organ of Corti, 83
Organ reed pipes:
Organum, 151
Orgelbuchlein, 274
Output, 168–169, 179, 181, 191, 215, 218, 222, 224
Overblown mode, 184, 191, 193, 194, 198, 199
Overtone, 126
P
Pain, threshold of, 24, 89, 90, 91
Parametric equalizer, 398
Partials of the waveform, 61
Partitions, sound isolation, 353–354
Passive noise cancellation, 416, 417
Pedal mixtur, 257
Perceptual coding systems, 264
Percussion instruments, 208
Perilymph fluid, 80
Periodic sound waves, spectrum of, 60–62
Periodic waveform, 122
Perturbation theory, 221
Phase locking, 144
Phase velocity, 12
Phon scale, 94
Piccolo, 194
Pitch perception:
basilar membrane, 133, 141, 142, 144, 146–147
duration effect, 149
fundamental frequency, 149
non-harmonic sounds, 136
Place theory of pitch perception, 133–137, 142
Plucked instruments, 180
Plucked string, sound source from, 172–173
Point sources, array of, 459–461
progressive phase shift, effect of, 464
visible region, 461
Polar pattern, surface size and illumination effect on, 459
array loudspeakers, 465
acoustic spatial filtering, 465–466
beamwidth, mouth/array, size effect on, 468–470
minimum beamwidth frequency as size function, 470
constant directivity horns, 467–468
diffuser design, 464
point sources, array of, 459–461
progressive phase shift, effect of, 464
visible region, 461
Pop concert effect, 43
Popping frequency, 205
Precedence effect, see Haas effect
Preludio, 266
Presbycusis, 89
Pressure:
sound wave nature, 3
standing wave components, 51
see also CompressionSound pressure level
Pressure antinodes, 52
Pressure node, 52
Pressure waves and sound transmission, 2
bars and panels, waves in, 10–14
sound waves, 3
relationship between pressure, velocity and impedance in, 18–21
wavelength and frequency of, 14–17
transverse wave, 9
Pressure-controlled valves, 197, 203
Protection of hearing, 106–107
proximity grouping, 265
Pseudo-lateral diffuse reflections, 318
Psychoacoustic models, 432
Psychoacoustic noise shaping, 431–432
Psychoacoustic quantization stage, 420, 428, 432–433
Psychoacoustic rating scales, 390–392
Psychoacoustic testing, 388
experimental design issues, 389–390
psychoacoustic rating scales, 390–392
speech intelligibility, 392–393
Psychoacoustics, definition of, 74
Public address systems, 402
intelligibility:
loudspeakers effect on, 404–405
reverberation effect on, 403–404
good speech intelligibility, requirements for, 407
measuring speech quality, methods for, 415
more than one loudspeaker and delays, 413–415
speaker directivity, achieving, 408–409
Pure-tone audiometry, 382, 386
Pure tones:
and speech audiometry, 381–388
Pythagoras’ theorem, 50
Q
Quadratic residue diffuser, 348
Quantization and adaptive quantization, 429–431
Quasi-longitudinal waves, 10–11
R
R, see Room constant
Radiation, sound, 181
Reflection:
bounded to unbounded boundaries, 46–47
Reflection controlled rooms, 369, 370–373
Reflection-free zones (RFZ), 370
absorption level required for, 373
absorption position for, 373–375
Register holes, recorder, 194
Relative loudness, 94
Repetition pitch, 149
Resultant bass, 273
balance to direct sound, 289–290
level in steady state, 290–295
Reverberation time, 299
calculation and prediction, 300–302
variation with frequency, 308–309
Reverberation time equation, derivation of, 451–454
for different frequencies and surfaces, 455–457
RFZ, see Reflection free zone
Room boundaries, on loudspeaker output, 356–358
Room modes and standing waves, 322
acoustically large rooms, 336
acoustically small rooms, 336
decay time of, 329–330, 333, 334
modes, behavior of, 329
universal modal frequency equation, 326–327
S
Sabine equation, 455
Sabine, Wallace Clement, 300, 304
Scattering, of sound, 58
Schroeder frequency, 336
SDS, see Speech Discrimination Score
“Sensorineural hearing loss”, 384
Septième, 243
Sesquialtera, 257
Shear modulus, 11
Shepherd tone, 270
Shift theorem, 461
Shoebox hall, 317
Side information, 420, 423, 430
Signal information, 420
Signal redundancy removal stage, 419, 421–424
Signal to masking ratio (SMR), 433
SII, see Speech intelligibility index
SIL, see Sound intensity level
Simple sounds, loudness of, 96–98
Simple tones, 247
Simultaneous masking, 263
Singer’s formant, 224
Single glazing, 353
Sinusoidal excitation, 14
SMR, see Signal to masking ratio
Snare drum, 213
Sony Super Bit Mapping, 432
Sony-SDDS, 419
Sound intensity, definition of, 37
Sound intensity level (SIL), 21–22
absorption, 44
hard boundaries, reflection from, 44–46
scattering, 58
unbounded boundaries, reflection from, 46–47
Sound isolation, 351
independent partitions, 353–354
Sound modifiers, 168
in percussion instruments, 209–216
in stringed instruments, 178–181
Sound power level (SWL), 23
Sound pressure, 24
Sound pressure level (SPL), 23–26, 410, 411, 412, 414
Sound source, 168
in percussion instruments, 208–209
Sound source direction, perception of, 107
interaural intensity difference, 111–113
interaural time difference, 107–111
pinnae and head movement effects, 111–114
stereophonic listening, 116–119
Sound waves:
relationship between pressure, velocity and impedance in, 18–21
wavelength and frequency of, 14–17
Speaking and singing voice, 216
sound modifiers, in singing, 219–225
sound source, in singing, 217–219
tuning in capella singing, 225–229
Spectra, analyzing, 64
time and frequency representations, 69–72
time responses, 69
Speech audiometry, 388
Speech Discrimination Score (SDS), 388
Speech intelligibility, 392–393
Speech intelligibility index (SII), 415
Speech quality measurement, methods for, 415
Speech Reception Threshold (SRT), 388
Speech transmission index (STI), 415
SPL, see Sound pressure level
Spring-loaded output key, 383
SRT, see Speech Reception Threshold
Stapes, 76
Stereophonic listening, 116–119
STI, see Speech transmission index
Stiffness-controlled isolation region, 352
Stirrup, 76
Streaming, see Grouping
Striations, 249
Stringed instruments, 170
bowed string, sound source from, 176–178
plucked string, sound source from, 172–173
struck string, sound source from, 173–176
Struck string, sound source from, 173–176
Subjective testing, 393
Summation, 34
Supra-aural headphones, 384
SWL, see Sound power level
Synthetic sounds, 216
T
Tap resonances, 179
Tchaikovsky’s 6th symphony, 266
Teen deterrents, 417
Temporal theory of pitch perception, 142–146
problems with, 146
Tenor saxophone, 237, 239, 243
Ternary diffuser, 464
Third order mode, 55
Threshold of hearing, 24, 91, 97, 382, 431
Tierce, 243
acoustics of, 233
deceiving the ear, 258
masking, one sound by another, 260–264
note grouping illusion, 264–270
pure tones, perception of, 258–260
psychoacoustics:
critical bands and timbre, 242–244
cues and timbre perception, 244–252
sound source modification, 399–400
synthesizer as pipe organ, 253–257
Time:
non-periodic sound waves, spectrum of, 63–64
periodic sound waves, spectrum of, 60–62
phase, effect of, 62
see also Reverberation time
Time domain effects, 396
Time domain prediction, 422
Timpani, 214
Tinnitus, noise-induced, 102
Tone-hole lattices, 199
Tosca, 240
Track listing, for audio compact disc, 473–478
Transverse wave, 9
Tristimulus diagram, 245
Tuba, 207
Tuning systems, 158
equal tempered tuning, 163–165
Turbulent airflow, 183
Two note chords, 131, 155, 157
Two-dimensional standing wave, 56
U
Uncorrelated sound sources, 27–28, 30–34
Universal modal frequency equation, 326–327
V
Velocity antinodes, 172
Vibration:
vocal Folds, 217–219, 222, 226
Vibrato, 219
Violin, 124, 170, 178–179, 181, 239, 241
Virtual pitch, 137
Visible region, of array of points, 461, 462, 463
Vocal tract, 217, 219, 220, 221, 222, 223, 224
cross-section of, 217
Voice, see Singing voice
Volley firing principle, 144
W
clarinet, 201
guitar, 180
reed organ pipes, 182
sawtooth, 178
Wavenumber, of sound waves, 17–18
Western harmony and harmonics, 150–151
Western music, 127, 151, 158, 228
Wideband absorbers, 343, 344, 345
Wiener–Khinchin theorem, 461, 464
Wind instruments, 181
organ flue pipes:
organ reed pipes:
woodwind flue instruments, 192–194
woodwind reed instruments, 197–202
Woodwind flue instruments, 192–194
Woodwind instruments, 198, 199, 237
Woodwind reed instruments, 197–202
X
Y