Cochlear Hearing Loss Physiological, Psychological and Technical Issues

by Moore, Brian C. J.

• ISBN13: 9780470516331
• ISBN10: 047051633X
• Edition: 2nd
• Format: Paperback
• Copyright: 2007-11-28
• Publisher: Wiley-Interscience

Summary

The book offers an understanding of the changes in perception that take place when a person has cochlear hearing loss. It interrelates physiological and perceptual data and presents both this and basic concepts in an integrated manner.

Author Biography

Brian C. J. Moore is in the Department of Experimental Psychology, University of Cambridge, England.

Table of Contents

Preface	p. xi
Physiological Aspects of Cochlear Hearing Loss	p. 1
Introduction	p. 1
Linear and Nonlinear Systems	p. 1
Structure and Function of the Outer and Middle Ear	p. 6
Structure and Function of the Normal Cochlea	p. 9
The cochlea, the basilar membrane and the organ of Corti	p. 9
Tuning on the basilar membrane	p. 12
The nonlinearity of input-output functions on the basilar membrane	p. 16
Two-tone suppression	p. 18
Combination tone generation	p. 18
Responses of the basilar membrane to complex sounds	p. 19
Otoacoustic emissions	p. 20
Neural Responses in the Normal Auditory Nerve	p. 21
Spontaneous firing rates and thresholds	p. 22
Tuning curves and iso-rate contours	p. 22
Rate-versus-level functions	p. 23
Two-tone suppression	p. 25
Phase locking	p. 26
Types of Hearing Loss	p. 28
Physiology of the Damaged Cochlea	p. 29
Basilar membrane responses	p. 29
Neural responses	p. 31
Structure-function correlation	p. 32
Otoacoustic emissions	p. 35
Phase locking	p. 35
Conclusions	p. 36
Absolute Thresholds	p. 39
Introduction	p. 39
Measures of Absolute Threshold	p. 39
Minimum audible pressure (MAP)	p. 39
Minimum audible field (MAF)	p. 39
Comparison of MAP and MAF	p. 40
The audiogram	p. 41
Descriptions of the Severity of Hearing Loss	p. 42
Causes of Hearing Loss Due to Cochlear Damage	p. 43
Perceptual Consequences of Elevated Absolute Thresholds	p. 44
Masking, Frequency Selectivity and Basilar Membrane Nonlinearity	p. 45
Introduction	p. 45
The Measurement of Frequency Selectivity Using Masking	p. 46
Introduction	p. 46
The power-spectrum model	p. 46
Estimating the shape of a filter	p. 47
Estimating Frequency Selectivity from Masking Experiments	p. 48
Psychophysical tuning curves	p. 48
The notched-noise method	p. 51
Characteristics of the Auditory Filter in Normal Hearing	p. 54
Variation with centre frequency	p. 54
Variation with level	p. 56
Summary	p. 59
Masking Patterns and Excitation Patterns	p. 59
Masking patterns	p. 59
Relationship of the auditory filter to the excitation pattern	p. 61
Changes in excitation patterns with level	p. 62
Possible effects of suppression	p. 63
Non-Simultaneous Masking	p. 64
Basic properties of non-simultaneous masking	p. 64
Evidence for suppression from non-simultaneous masking	p. 67
The enhancement of frequency selectivity revealed in non-simultaneous masking	p. 69
Relation between the growth of forward masking and the basilar membrane input-output function	p. 70
The Audibility of Partials in Complex Tones	p. 73
Effects of Cochlear Damage on Frequency Selectivity in Simultaneous Masking	p. 75
Complicating factors	p. 75
Psychophysical tuning curves	p. 76
Auditory filter shapes measured with notched noise	p. 79
The Use of Masking to Diagnose Dead Regions	p. 83
The threshold-equalizing noise (TEN) test	p. 83
The TEN(HL) test	p. 85
Prevalence of dead regions assessed using the TEN(HL) test	p. 86
Effects of Cochlear Damage on Forward Masking and Suppression	p. 86
Effects of Cochlear Hearing Loss on BM Input-output Functions 88 XII Perceptual Consequences of Reduced Frequency Selectivity, Dead Regions, Loss of Suppression and Steeper BM Input-output Functions	p. 90
Susceptibility to masking	p. 90
Timbre perception	p. 90
Perceptual consequences of dead regions	p. 91
Loudness Perception and Intensity Resolution	p. 93
Introduction	p. 93
Loudness Perception for Normally Hearing People	p. 93
Equal-loudness contours and loudness level	p. 93
The scaling of loudness	p. 94
The detection of intensity changes	p. 96
Effects of Cochlear Hearing Loss on Loudness Perception	p. 97
A Model of Normal Loudness Perception	p. 101
A Model of Loudness Perception Applied to Cochlear Hearing Loss	p. 104
Introduction	p. 104
Elevation of absolute threshold	p. 105
Reduced compressive nonlinearity	p. 105
Reduced inner hair cell/neural function	p. 106
Reduced frequency selectivity	p. 107
Complete loss of functioning IHCs or neurones (dead regions)	p. 108
Using the model to account for loudness recruitment	p. 109
Effects of Bandwidth on Loudness	p. 110
Normal hearing	p. 110
Impaired hearing	p. 111
Effects of Cochlear Hearing Loss on Intensity Resolution	p. 113
Perceptual Consequences of Altered Loudness Perception	p. 114
Consequences of loudness recruitment and reduced dynamic range	p. 114
Perceptual consequences of reduced loudness summation	p. 114
Perceptual consequences of altered intensity discrimination	p. 115
Temporal Resolution and Temporal Integration	p. 117
Introduction	p. 117
Modelling Within-Channel Temporal Resolution in Normal Hearing	p. 118
Bandpass filtering	p. 118
The nonlinearity	p. 119
The sliding temporal integrator	p. 120
The decision device	p. 122
Characterizing the nonlinear device and the sliding temporal integrator	p. 122
Temporal Resolution in Normal Hearing	p. 124
The effect of centre frequency on gap detection	p. 124
Temporal modulation transfer functions	p. 125
The rate of recovery from forward masking	p. 126
Temporal Resolution in People with Cochlear Damage	p. 128
The influence of sound level on gap detection and the rate of decay of forward masking	p. 128
The influence of audible bandwidth on temporal modulation transfer functions and gap detection	p. 130
The influence of changes in the compressive nonlinearity	p. 131
Temporal Integration at Threshold	p. 135
Temporal integration in normally hearing people	p. 135
Temporal integration in people with cochlear hearing loss	p. 136
Explanations for reduced temporal integration in people with cochlear hearing loss	p. 137
Temporal Integration at Suprathreshold Levels	p. 138
Perceptual Consequences of Abnormal Temporal Processing in People with Cochlear Hearing Loss	p. 140
Consequences of abnormal temporal resolution	p. 140
Consequences of reduced temporal integration	p. 141
Pitch Perception and Frequency Discrimination	p. 143
Introduction	p. 143
Theories of Pitch Perception	p. 144
The Perception of the Pitch of Pure Tones by Normally Hearing People	p. 144
The frequency discrimination of pure tones	p. 144
The perception of musical intervals	p. 148
The effect of level on pitch	p. 149
Frequency Discrimination of Pure Tones by People with Cochlear Hearing Loss	p. 150
Difference limens for frequency (DLFs)	p. 150
Frequency modulation detection limens (FMDLs)	p. 152
The Perception of Pure-Tone Pitch for Frequencies Falling in a Dead Region	p. 155
Pitch Anomalies in the Perception of Pure Tones	p. 157
The Pitch Perception of Complex Tones by Normally Hearing People	p. 159
The phenomenon of the missing fundamental	p. 159
Discrimination of the repetition rate of complex tones	p. 159
Theories of Pitch Perception for Complex Tones	p. 160
The representation of a complex tone in the peripheral auditory system	p. 160
Spectro-temporal pitch theories	p. 162
The relative importance of envelope and temporal fine structure	p. 164
Pitch Perception of Complex Tones by People with Cochlear Hearing Loss	p. 167
Theoretical considerations	p. 167
Experimental studies	p. 169
Perceptual Consequences of Altered Frequency Discrimination and Pitch Perception	p. 170
Effects on speech perception	p. 170
Effects on music perception	p. 172
Spatial Hearing and Advantages of Binaural Hearing	p. 173
Introduction	p. 173
The Localization of Sinusoids	p. 174
Cues for localization	p. 174
Performance of normally hearing people in localization and lateralization	p. 177
Performance of hearing-impaired people in localization and lateralization	p. 178
The Localization of Complex Sounds	p. 179
The role of transients and across-frequency comparisons	p. 179
Performance of normally hearing people	p. 179
Performance of people with cochlear hearing loss	p. 180
Reasons for large interaural time difference and interaural level difference thresholds in people with cochlear hearing loss	p. 183
The Cone of Confusion, Head Movements and Pinna Cues	p. 184
The cone of confusion	p. 184
The role of head movements	p. 185
Information provided by the pinnae	p. 185
Localization using pinna cues by normally hearing and hearing-impaired people	p. 186
General Conclusions on Sound Localization	p. 186
The Precedence Effect	p. 187
The precedence effect for normal hearing	p. 187
The precedence effect for impaired hearing	p. 188
Binaural Masking Level Differences (MLDs)	p. 189
MLDs for normally hearing people	p. 189
Mechanisms underlying MLDs	p. 192
MLDs for people with cochlear hearing loss	p. 192
Possible reasons for smaller MLDs in people with cochlear damage	p. 193
Head-Shadow Effects	p. 194
Benefits of head shadow for normally hearing people	p. 194
Benefits of head shadow for hearing-impaired people	p. 195
Release from Informational Masking	p. 196
Diotic Advantages	p. 198
Perceptual Consequences of Abnormal Binaural and Spatial Hearing in People with Cochlear Damage	p. 199
Speech Perception	p. 201
Introduction	p. 201
The Magnitude of the Noise Problem	p. 201
The Role of Audibility	p. 203
The Articulation Index (AI) and Speech Intelligibility Index (SII)	p. 203
Use of the AI or SII to predict speech intelligibility for the hearing impaired	p. 204
The intelligibility of speech in noise at high overall levels	p. 205
Comparison of detection and recognition for speech in noise	p. 206
The intelligibility of speech in quiet at high overall levels	p. 207
Simulation of hearing loss by selective filtering (frequency-dependent attenuation)	p. 207
Simulation of hearing loss by masking	p. 208
Conclusions on the role of audibility	p. 209
Influence of Dead Regions on Speech Perception	p. 209
Correlation Between Psychoacoustic Abilities and Speech Perception	p. 212
Assessing the Effects of Frequency Selectivity on Vowel and Consonant Perception	p. 214
Consonant perception	p. 214
Vowel perception	p. 215
Influence of Loss of Sensitivity to Temporal Fine Structure	p. 219
The Use of Simulations to Assess the Importance of Psychoacoustic Factors in Speech Perception	p. 221
Simulations of loudness recruitment combined with threshold elevation	p. 222
Simulations of reduced frequency selectivity	p. 226
Simulation of the combined effects of threshold elevation, recruitment and reduced frequency selectivity	p. 229
Simulation of reduced temporal resolution	p. 230
Conclusions	p. 232
Hearing Aids	p. 233
Introduction	p. 233
Linear Amplification	p. 233
The difficulty of restoring audibility using linear aids	p. 233
Prescriptive fitting rules for linear hearing aids	p. 234
Compression Amplification	p. 236
Basic characteristics of automatic gain control systems	p. 236
Varieties of automatic gain control systems	p. 241
Rationales for the use of multi-band compression (and noise reduction)	p. 241
Research on the effectiveness of multi-band syllabic compression	p. 242
Methods for initial fitting of hearing aids with multi-band compression	p. 244
Methods for fine tuning hearing aids with multi-band compression	p. 252
Slow-acting automatic gain control systems	p. 253
Comparisons of slow-acting and fast-acting systems	p. 255
General conclusions about compression	p. 257
Some General Problems with Hearing Aids	p. 257
Inadequate gain at high frequencies	p. 257
Acoustic feedback	p. 258
Peakiness of frequency response	p. 259
The occlusion effect	p. 260
Time delays	p. 261
Methods for Improving the Speech-to-Noise Ratio	p. 262
Multi-channel noise reduction	p. 262
Directional microphones	p. 262
Binaural processing algorithms	p. 263
Transposition Aids for Severe and Profound Hearing Loss	p. 264
Cochlear Implants	p. 266
Concluding Remarks	p. 267
Glossary	p. 269
References	p. 287
Index	p. 327
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