E-Book, Englisch, 722 Seiten
Reihe: ISSN
Fundamental Organization and Clinical Disorders
E-Book, Englisch, 722 Seiten
Reihe: ISSN
ISBN: 978-0-444-62629-5
Verlag: Elsevier Reference Monographs
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)
A focused reference on the neuroscience of hearing and clinical disordersCovers both basic brain science, key methodologies and clinical diagnosis and treatment of audiology disordersCoverage of audiology across the lifespan from birth to elderly topics
Autoren/Hrsg.
Weitere Infos & Material
1;Front Cover;1
2;The Human Auditory System: Fundamental Organization and Clinical Disorders;4
3;Copyright;5
4;Handbook of Clinical Neurology 3rd Series;6
5;Foreword;8
6;Preface;10
7;Contributors;12
8;Contents;16
9;Section 1: Anatomy and Physiology of the Human Auditory System;20
9.1;Chapter 1: Auditory Pathways: Anatomy and Physiology;22
9.1.1;Introduction and Overview;22
9.1.2;The Outer and Middle ears;22
9.1.2.1;The Absolute Threshold and Relation to outer- and middle-ear Transmission;22
9.1.3;The Cochlea;23
9.1.3.1;Overall Anatomy;23
9.1.3.2;Anatomy in Relation to Function;23
9.1.3.3;The Output of the Cochlea;25
9.1.4;The Auditory Central Nervous System: Introduction to Central Processing;26
9.1.5;The Ventral Auditory Stream Of the Brainstem; Sound Localization By Comparing Responses At the Two ears;27
9.1.5.1;The Anteroventral Cochlear Nucleus;27
9.1.5.2;The Medial Superior olive;28
9.1.5.3;The Lateral Superior olive;29
9.1.5.4;Outputs of the Ventral Auditory Stream of the Brainstem;29
9.1.6;The Dorsal Auditory Stream of the Brainstem: Complex Stimulus Analysis;30
9.1.6.1;The Dorsal Cochlear Nucleus;30
9.1.6.2;The Posteroventral Cochlear Nucleus;30
9.1.6.3;The Ventral Nucleus of the Lateral Lemniscus;31
9.1.7;The Inferior Colliculus;31
9.1.7.1;The Central Nucleus of the Inferior Colliculus;31
9.1.7.2;The External Nucleus and Dorsal Cortex of the Inferior Colliculus;32
9.1.8;The Medial Geniculate body;32
9.1.8.1;Overall Anatomy and Inputs;33
9.1.8.2;The Ventral Nucleus;33
9.1.8.2.1;Anatomy and Frequency Organization;33
9.1.8.2.1.1;Responses To sound;34
9.1.8.2.2;The Medial and Dorsal Nuclei of the MGB;34
9.1.9;The Auditory Cortex;34
9.1.9.1;Anatomic Introduction to the Auditory Cortex;36
9.1.9.2;Tonotopic Organization;36
9.1.9.3;Organization Along frequency-band Strips;37
9.1.9.4;Responses of Single Neurons: Responses In the core;37
9.1.9.5;Responses of Single Neurons: Responses In the belt;37
9.1.9.6;Cortical Processing of Sound Location;38
9.1.9.7;Cortical Processing in Relation to Stimulus Complexity;38
9.1.10;The Centrifugal System;40
9.1.11;References;41
9.2;Chapter 2: Anatomic Organization of the Auditory Cortex;46
9.2.1;What is Auditory Cortex?;47
9.2.2;Principles of Auditory Cortical Organization;47
9.2.2.1;Principle 1: Auditory Cortex Can Be Divided Into Regions;48
9.2.2.2;Principle 2: Regions of Auditory Cortex Are subdivided Into areas;49
9.2.2.3;Principle 3: Individual Areas of Auditory Cortex are Tonotopically Organized;50
9.2.2.4;Principle 4: Thalamic Inputs to Auditory Cortex Vary By Region And layer;51
9.2.2.4.1;MGv;52
9.2.2.4.2;MGd;52
9.2.2.4.3;MGm;52
9.2.2.5;Principle 5: The Connections of Auditory Cortex have Serial and Parallel Features;52
9.2.2.5.1;Serial Connections and Hierarchic Relationships;53
9.2.2.5.2;Core–belt–parabelt axis;53
9.2.2.5.3;Caudal–rostral axis;54
9.2.2.5.4;Parallel Connections;54
9.2.2.6;Principle 6: The auditory-related Connections of Auditory Cortex are Topographically Organized;54
9.2.2.6.1;Superior Temporal Cortex;55
9.2.2.6.2;Prefrontal and Cingulate Cortex;56
9.2.2.6.3;Posterior Parietal Cortex;56
9.2.2.6.4;Occipital Cortex;56
9.2.2.6.5;Anterior Parietal Cortex;57
9.2.2.6.6;Striatum;57
9.2.2.6.7;Amygdala;58
9.2.2.6.8;Functional Considerations;58
9.2.3;Correspondence of Human and non-human Primate Auditory Cortex;60
9.2.3.1;Where is Auditory Cortex in the Human brain?;60
9.2.3.2;Regions And areas;61
9.2.4;Concluding Remarks;63
9.2.5;Acknowledgments;64
9.2.6;References;64
9.3;Chapter 3: Development of the Auditory System;74
9.3.1;Introduction;74
9.3.2;Development of The ear;75
9.3.3;Behavioral Testing and Psychoacoustics;75
9.3.4;Coding of Auditory Features;78
9.3.4.1;Detection Of sound;78
9.3.4.2;Frequency and Intensity Discrimination;78
9.3.4.3;Loudness;79
9.3.5;Masking and Auditory Segregation;79
9.3.5.1;Background on Grouping and Segregation;79
9.3.5.2;Energetic Masking;80
9.3.5.3;Auditory Streaming;80
9.3.5.4;Co-modulation Masking Release;80
9.3.5.5;Informational Masking;81
9.3.5.6;Backward Masking and Auditory Maturation;82
9.3.6;Spatial and Binaural Hearing;83
9.3.6.1;Binaural cues;83
9.3.6.2;Measuring Localization;83
9.3.6.3;Developmental Findings on Localization;84
9.3.6.4;Binaural Unmasking;85
9.3.6.5;The Precedence Effect;86
9.3.7;Relationship Between Age of Development and Desirable Age of Intervention in Deaf Children;87
9.3.8;Conclusions;88
9.3.9;Acknowledgment;88
9.3.10;References;88
9.4;Chapter 4: Representation of Loudness in the Auditory Cortex;92
9.4.1;Introduction;92
9.4.2;Psychophysics;94
9.4.3;Animal Physiology;95
9.4.4;Human Cortical Studies;99
9.4.5;Acknowledgments;102
9.4.6;References;102
9.5;Chapter 5: Temporal Coding in the Auditory Cortex;104
9.5.1;Overview;104
9.5.1.1;Timescales in Auditory Perception;104
9.5.1.2;The Temporal Structure of Speech Sounds;105
9.5.2;Encoding of Spectrotemporal Features in the Auditory Cortex;107
9.5.2.1;Sensitivity to Temporal Modulations In the primary Auditory Cortex;107
9.5.2.2;Sensitivity to Spectrotemporal Modulations;107
9.5.3;Cortical Processing of Continuous Sound Streams;108
9.5.3.1;The Discretization Problem;108
9.5.3.2;Analysis At Multiple Timescales;109
9.5.3.3;Neural Oscillations as Endogenous Temporal Constraints;110
9.5.3.4;Alignment of Neuronal Excitability With Speech Timescales;111
9.5.3.5;Parallel Processing At Multiple Timescales;111
9.5.3.6;Parallel Processing in Bilateral Auditory Cortices;113
9.5.3.7;Dysfunctional Oscillatory Sampling;114
9.5.4;Conclusion;114
9.5.5;References;115
9.6;Chapter 6: Sound Localization;118
9.6.1;Introduction;118
9.6.2;Some Terms and Techniques;118
9.6.3;Horizontal Localization;119
9.6.3.1;Duplex Theory;119
9.6.3.2;Interaural time-difference cues;120
9.6.3.3;Interaural level-difference cues;121
9.6.3.4;Monaural Conditions;122
9.6.4;Vertical and Front/back Localization;122
9.6.5;Distance Localization;123
9.6.6;Motion Perception;124
9.6.7;Localization in Reverberant Spaces: the Precedence Effect;126
9.6.8;Central Representation of sound-source Locations;126
9.6.8.1;Spatial Topography in the Superior Colliculus;126
9.6.8.2;Distributed Spatial Representation in the Auditory Cortex;127
9.6.8.3;Cortical Areas Specialized for Sound Localization;129
9.6.9;Beyond Localization;130
9.6.10;References;131
9.7;Chapter 7: New Perspectives on the Auditory Cortex: Learning and Memory;136
9.7.1;Introduction;136
9.7.2;Basic Considerations and Early Findings;137
9.7.2.1;Introduction;137
9.7.2.2;Background Findings;137
9.7.3;Contemporary Approaches: Representational Plasticity;138
9.7.3.1;A Synthesis of Two Disciplines;138
9.7.3.2;Representational Plasticity Reveals Specificity of Auditory Cortical Dynamics;139
9.7.3.3;Representational Plasticity Across Species;139
9.7.4;Isn't All Auditory Learning Actually perceptual Learning?;141
9.7.5;Does the Primary Auditory Cortex Hold Specific Memory Traces?;141
9.7.5.1;Forms of Representational Plasticity;141
9.7.5.2;Basic Considerations of Specific Memory Traces;142
9.7.5.2.1;Cardinal Characteristics of Representational Plasticity;143
9.7.5.2.2;Generality Across Types of Acoustic Stimulus Parameters;144
9.7.5.2.3;Generality Across Motivational States and Tasks;145
9.7.5.3;Multiple Rule Tasks and the Role of Learning Strategy;145
9.7.5.3.1;Reversal and Loss of Representational Gain in A1;146
9.7.5.3.2;Individual Vs Group Analysis;146
9.7.5.3.3;Three Classes of Auditory Tasks and Representational Plasticity;148
9.7.6;Functions of Representational Plasticity in the Primary Auditory Cortex;149
9.7.6.1;Encoding the Behavioral Importance Of a sound;149
9.7.6.2;Reinforcement Prediction;149
9.7.6.3;Substrate of Memory Strength;150
9.7.7;Arguments to the Contrary;150
9.7.7.1;Is Representational Plasticity Caused By Fear Or Increased Arousal?;151
9.7.7.2;Are Tuning Shifts Spontaneous, Not Induced By Learning?;151
9.7.7.3;``But, Cortical Lesions Dont Prevent Memory´´;152
9.7.8;Mechanisms of Representational Plasticity and Specific Auditory Memory;153
9.7.8.1;Neuromodulators in Representational Plasticity;153
9.7.8.1.1;Acetylcholine;153
9.7.8.1.2;Ach and Representational Plasticity;153
9.7.8.1.3;Ach and the Implantation of Specific Associative Behavioral Memory;154
9.7.8.2;Neural Synchrony and gamma-band Oscillations;156
9.7.8.3;Circuit and Synaptic Processes;156
9.7.9;Implications for Treatment of Auditory and Related Disorders;157
9.7.9.1;Memory Strength and Posttraumatic Stress Disorder;158
9.7.9.2;Gamma-band Oscillations in Assessment And treatment;158
9.7.9.3;Cholinergic Implantation of Specific Memory;158
9.7.9.4;Individualized Analyses of Neural Plasticity, Learning, and Memory;159
9.7.10;Conclusions and General Implications;159
9.7.10.1;Primary Auditory Cortex, Learning, and Plasticity;159
9.7.10.2;Beyond Perception: the Acquisition of Meaning To sound;159
9.7.10.3;Reconceptualizing the Primary Auditory Cortex;160
9.7.10.4;Toward a New Model of the Cerebral Cortex;160
9.7.11;Acknowledgments;160
9.7.12;References;161
9.8;Chapter 8: Neural Basis of Speech Perception;168
9.8.1;Introduction;168
9.8.2;The dual-route Model of Speech Processing;168
9.8.2.1;Ventral Stream: Mapping From Sound To meaning;168
9.8.2.1.1;Bilateral Organization and Parallel Computation;168
9.8.2.1.2;Computational Asymmetries;169
9.8.2.1.3;Phonologic Processing and the Superior Temporal Sulcus;170
9.8.2.1.4;Exical -Semantic Access;171
9.8.2.2;Dorsal Stream: Mapping From Sound To action;172
9.8.2.2.1;The Need for Auditory-motor Integration;172
9.8.3;Clinical Correlates of the dual-stream model;175
9.8.4;Sex Differences in Language Organization;176
9.8.5;Summary;176
9.8.6;References;176
9.9;Chapter 9: Role of the Auditory System in Speech Production;180
9.9.1;Introduction;180
9.9.2;The Planning of Speech Movements;181
9.9.3;Brain Regions Involved in Speech Articulation;182
9.9.4;Neurocomputational Models Of speech Production;182
9.9.4.1;The Directions Into Velocities Of Articulators model;183
9.9.4.1.1;Auditory Feedback Control;184
9.9.4.1.2;Somatosensory Feedback Control;186
9.9.4.1.3;Feedforward Control;186
9.9.4.2;The GODIVA Model of Speech Sound Sequencing;188
9.9.4.3;The Hierarchical State Feedback Control model;188
9.9.4.4;Future Directions;190
9.9.5;Acknowledgments;191
9.9.6;References;191
9.10;Chapter 10: White-matter Pathways for Speech and Language Processing;196
9.10.1;Introduction;196
9.10.2;The language-relevant Brain Regions;197
9.10.2.1;Left Frontal Cortex;197
9.10.2.2;Left Temporal Cortex;198
9.10.2.3;Left Parietal Cortex;198
9.10.3;The Language Pathways;198
9.10.3.1;Dorsal Pathway;199
9.10.3.2;Ventral Pathway;201
9.10.4;Conclusions;203
9.10.5;References;203
9.11;Chapter 11: Neural Basis of Music Perception;206
9.11.1;Introduction;206
9.11.1.1;Music and the Auditory scene;206
9.11.1.2;Summarizing the Literature;206
9.11.1.3;A meta-analysis of the Neuroimaging Literature;207
9.11.2;Musical Properties of Isolated Auditory Objects;207
9.11.2.1;Pitch Chroma;207
9.11.2.2;Timbre;209
9.11.3;Complex Musical Objects and Their Combination;211
9.11.3.1;Interval, Contour, and Melody;212
9.11.3.1.1;Familiar Melodies;216
9.11.3.1.2;Melody and Song;216
9.11.3.2;Harmony And key;216
9.11.3.3;Harmonic Sequences;217
9.11.3.4;Rhythm And meter;217
9.11.4;Musical Expertise and Plasticity in the Auditory Cortex;218
9.11.5;Music Beyond the Auditory Cortex;221
9.11.6;Acknowledgments;221
9.11.7;References;221
9.12;Chapter 12: Music and Language: Relations and Disconnections;226
9.12.1;Introduction;226
9.12.2;Music and Language: Structural and Functional Origins;226
9.12.2.1;Structure Rooted In sound;226
9.12.2.2;Communication in Context;227
9.12.3;Temporal Processing in Music And language;227
9.12.3.1;Rhythm as a ``temporal map´´;228
9.12.3.1.1;Regularity and Variability in Temporal Structure;228
9.12.3.2;Neural Basis of Temporal Processing: Oscillatory Rhythms;229
9.12.4;Music and Language: Models of Learning and Plasticity;230
9.12.4.1;Rule-based Learning;230
9.12.4.1.1;Learning Trajectories in Music and Language;231
9.12.5;Neural Plasticity: the Interactive Auditory System;231
9.12.5.1;The Auditory Brainstem: Hub of Auditory Information Processing;232
9.12.5.2;Selective Enhancement: Neural Signatures Of auditory Expertise;232
9.12.5.2.1;Musical Expertise;232
9.12.5.2.2;Bilingualism;233
9.12.5.3;Neural Underpinnings of Language Ability And impairment;234
9.12.5.4;Clinical Implications;235
9.12.6;Conclusions;235
9.12.7;Acknowledgments;236
9.12.8;References;236
10;Section 2: Methodology and Techniques;242
10.1;Chapter 13: Invasive Recordings in the Human Auditory Cortex;244
10.1.1;Introduction;244
10.1.2;Historic Overview;245
10.1.3;Research Subjects;246
10.1.4;Acute Experiments;247
10.1.5;Chronic Experiments;247
10.1.6;Data Analysis;251
10.1.7;Studies of Spectrotemporal Processing: Electrophysiologic Recording;253
10.1.8;Functional Connectivity Studies: Modeling and Electric Stimulation Tract Tracing;257
10.1.9;Functional Lesioning Studies: Electric Stimulation Mapping and Cortical Cooling;258
10.1.10;Caveats of the Method and Validity of Invasive Recordings;259
10.1.11;Conclusion;260
10.1.12;Acknowledgments;260
10.1.13;References;260
10.2;Chapter 14: Electromagnetic Recording of the Auditory System;264
10.2.1;Introduction;264
10.2.2;Electrophysiologic Recording;265
10.2.3;Magnetoencephalography;265
10.2.4;Auditory Research Using MEG;267
10.2.4.1;Transient Evoked Responses: N100m (M100), P2m, M350, N400m (M400);267
10.2.4.2;``Transition´´ Responses: Pitch Onset Response, Change Response, Mismatch Response;268
10.2.4.3;Auditory steady-state Responses;270
10.2.4.4;Oscillations;270
10.2.5;Conclusion;271
10.2.6;References;272
10.3;Chapter 15: Hemodynamic Imaging of the Auditory Cortex;276
10.3.1;Introduction;276
10.3.2;Applications of Fmri to Investigate Central Auditory Function;276
10.3.3;Key Principles of Magnetic Resonance Imaging;277
10.3.3.1;What Is MRI?;277
10.3.3.2;What Is fMRI?;278
10.3.3.3;Scanning Parameters;278
10.3.4;Practical Considerations in Optimizing the signal-to-noise Ratio of Auditory fMRI;280
10.3.4.1;Field Strength;280
10.3.4.2;Radiofrequency coils;281
10.3.4.3;Voxel size;281
10.3.4.4;Number of Acquisitions;281
10.3.4.5;Receiver Bandwidth;282
10.3.5;Practical Considerations in Optimizing the Quality Of Auditory fMRI Data;282
10.3.5.1;Reducing the Impact of Scanner Acoustic noise;282
10.3.5.1.1;Sparse Imaging;283
10.3.5.1.2;Noise Cancellation;283
10.3.5.2;Cardiac Gating for fMRI in Subcortical Auditory Structures;283
10.3.6;Experimental Designs;284
10.3.6.1;Categorical Designs;284
10.3.6.2;Factorial Designs;285
10.3.6.3;Parametric Designs;286
10.3.6.4;Adaptation Designs;286
10.3.7;Analysis;287
10.3.7.1;Spatial Preprocessing;288
10.3.7.2;Statistical Analyses;289
10.3.7.2.1;General Linear Model;289
10.3.7.2.2;Individual and Group-level Analyses;290
10.3.7.2.3;Statistical Inference;291
10.3.7.2.4;Plotting Statistical Results and Multiple Voxel Comparisons;291
10.3.7.2.5;Comparisons Between Brain Regions;291
10.3.8;Concluding Remarks;292
10.3.9;Acknowledgments;293
10.3.10;References;293
10.4;Chapter 16: Imaging white-matter Pathways of the Auditory System With diffusion Imaging Tractography;296
10.4.1;Introduction;296
10.4.2;Diffusion MRI Tractography;297
10.4.2.1;Diffusion Magnetic Resonance Imaging;297
10.4.2.2;Diffusion Tensor Imaging;298
10.4.2.3;Non-tensorial Diffusion Models;299
10.4.2.4;Diffusion Imaging Tractography;299
10.4.2.5;Two Different Approaches: Deterministic And probabilistic Tractography;301
10.4.3;Tractography Reconstructions of the Auditory Pathways;301
10.4.4;Conclusions and Future Directions;304
10.4.5;Acknowledgments;305
10.4.6;References;305
10.5;Chapter 17: Electrophysiologic Auditory tests;308
10.5.1;Introduction;308
10.5.2;Electrocochleogram;308
10.5.2.1;Components of the Electrocochleogram;309
10.5.2.1.1;Cochlear Microphonic;309
10.5.2.1.2;Cochlear Summating Potential;310
10.5.2.1.3;Eighth-nerve Compound Action Potential;311
10.5.2.2;Clinical Applications of Electrocochleography;311
10.5.2.2.1;Measurement of Hearing;311
10.5.2.2.2;Me´nie` re’s Disease;312
10.5.2.2.3;Auditory Neuropathy;312
10.5.2.2.4;Intraoperative Monitoring;312
10.5.3;Brainstem Auditory Evoked Potentials;313
10.5.3.1;BAEP Generators;313
10.5.3.2;BAEP Recording Techniques;315
10.5.3.2.1;Stimulation;315
10.5.3.2.2;Recording;317
10.5.3.3;Interpretation of BAEP Studies;317
10.5.3.3.1;Component Identification;317
10.5.3.3.2;Interpretation of Extraoperative Diagnostic Studies;318
10.5.3.3.3;Interpretation of Intraoperative BAEP Monitoring;319
10.5.3.4;Frequency-following Responses;320
10.5.4;Middle-latency Auditory Evoked Potentials;321
10.5.4.1;Components and Generators;321
10.5.4.2;Clinical Utility;323
10.5.5;Long-latency Auditory Evoked Potentials;323
10.5.5.1;The P1–N1–P2–N2 Complex;323
10.5.5.2;The Mismatch Negativity;324
10.5.5.3;The P3/P300 Component;325
10.5.5.4;Clinical and Research Applications;326
10.5.6;References;327
10.6;Chapter 18: Psychophysical and Behavioral Peripheral and Central Auditory tests;332
10.6.1;Introduction;332
10.6.2;Peripheral tests;332
10.6.2.1;Standard pure-tone Thresholds and Speech Recognition tests;332
10.6.2.2;Otoacoustic Emissions;333
10.6.2.3;The Acoustic Reflex;333
10.6.3;Central Auditory tests;334
10.6.3.1;Dichotic Listening;334
10.6.3.1.1;Dichotic Findings in Individuals With Normal Peripheral and Central Auditory Function;334
10.6.3.1.2;Methodologic Factors;334
10.6.3.1.3;Findings in Clinical Populations;335
10.6.3.2;Binaural Interaction Procedures;335
10.6.3.2.1;Masking Level Differences;336
10.6.3.2.2;Localization and Lateralization;336
10.6.3.2.3;Spatial Listening;337
10.6.3.3;Temporal Processing tests;338
10.6.3.3.1;Temporal Ordering or Sequencing;338
10.6.3.3.2;Temporal Resolution or Discrimination;339
10.6.3.3.3;Temporal Integration;340
10.6.3.3.4;Temporal Masking;340
10.6.3.4;Monaural low-redundancy tests;341
10.6.3.4.1;Classification of Monaural Low-redundancy Speech Tests;341
10.6.3.4.2;Low-pass Filtered Speech tests;342
10.6.3.4.3;Speech-in-competition (speech-in-noise) tests;342
10.6.3.4.4;Synthetic Sentence Identification test;343
10.6.3.4.5;Pediatric Speech Intelligibility test;343
10.6.3.4.6;Other speech-in-noise tests;343
10.6.3.4.7;Time-compressed Speech tests;344
10.6.4;Psychophysical Tests in Electrophysiologic Paradigms;345
10.6.5;Cost-effectiveness;345
10.6.6;Summary and Conclusions;345
10.6.7;References;347
11;Section 3: Disorders of the Auditory System;352
11.1;Chapter 19: Neurocognitive Development in Congenitally Deaf Children;354
11.1.1;Introduction;354
11.1.2;Prevalence and Epidemiology;354
11.1.2.1;Onset of Hearing loss;354
11.1.2.2;Progressive Hearing loss;355
11.1.2.3;Type of Hearing loss;356
11.1.2.4;Severity of Hearing loss;356
11.1.2.5;Hearing Loss and Additional Disabilities;356
11.1.3;Effects of Permanent Childhood Hearing Loss on the Child and Family;357
11.1.3.1;Auditory Plasticity;357
11.1.3.2;Sensitive Period for Language Learning;358
11.1.3.3;Impact on Child's Experience in the Family;359
11.1.4;Current Context for Children With Hearing loss;361
11.1.4.1;Neonatal Hearing Screening;361
11.1.4.2;Cochlear Implantation;361
11.1.4.3;Expectations;361
11.1.4.4;Summary;362
11.1.5;Factors Affecting Neurocognitive Development;362
11.1.5.1;Approaches to Neurodevelopmental Rehabilitation;363
11.1.6;Audition and Spoken Language;363
11.1.6.1;Children With Mild to Severe Degrees Of hearing loss;363
11.1.6.2;Children With Mild Bilateral and Unilateral Hearing loss;365
11.1.6.3;Children With Cochlear Implants;366
11.1.6.3.1;Reasons for Late Implantation;367
11.1.6.4;Literacy Development;368
11.1.7;Cognition and Learning;368
11.1.7.1;Cognitive Functioning in Children With cochlear Implants;369
11.1.7.2;Theory of Mind and Social Development;370
11.1.8;Summary;371
11.1.9;Acknowledgments;371
11.1.10;References;371
11.2;Chapter 20: Aging of the Auditory System;376
11.2.1;General Aspects Of aging;376
11.2.2;Definition and Terminology;377
11.2.3;Epidemiology;377
11.2.4;Histopathologic Changes and Schuknecht's Classification;379
11.2.4.1;Sensory Presbycusis;379
11.2.4.2;Neural Presbycusis;379
11.2.4.3;Strial Presbycusis;380
11.2.4.4;Atrophy of the Spiral Ligament;380
11.2.4.5;Indeterminant Presbycusis;381
11.2.4.6;Mixed Presbycusis;381
11.2.4.7;Cochlear Conductive Presbycusis;382
11.2.5;Aging of the Peripheral Auditory System;383
11.2.5.1;Oxidative Stress;383
11.2.5.2;Genetics;384
11.2.5.3;Mitochondria;384
11.2.5.4;Endocochlear Potential;385
11.2.5.5;Fibrocytes and Fibroblast Growth factor;386
11.2.5.6;Gender and Hormones;387
11.2.6;Aging of the Central Auditory System;388
11.2.6.1;Auditory Cortex;388
11.2.6.2;Theory of Cortical Disconnection;388
11.2.6.3;Calcium Homeostasis;388
11.2.7;Diagnosis and Clinical Manifestation;389
11.2.8;Rehabilitation;389
11.2.9;Consequences Of arhl;390
11.2.10;References;390
11.3;Chapter 21: Decreased Sound Tolerance: Hyperacusis, Misophonia, Diplacousis, and Polyacousis;394
11.3.1;Introduction;394
11.3.2;Definitions;394
11.3.3;Decreased Sound Tolerance (hyperacusis and Misophonia), Diplacousis, and Polyacousis as a Problem;396
11.3.4;Diagnosis;397
11.3.5;Prevalence and Epidemiology;399
11.3.6;Mechanisms;399
11.3.7;The Neurophysiological Model of Decreased Sound Tolerance;402
11.3.8;Treatments;402
11.3.8.1;Tinnitus Retraining Therapy (TRT) for Decreased Sound Tolerance;403
11.3.9;Conclusions;404
11.3.10;References;404
11.4;Chapter 22: Auditory Synesthesias;408
11.4.1;Introduction;408
11.4.2;Types of Synesthesia;408
11.4.2.1;Consistency;408
11.4.2.2;Automaticity;408
11.4.2.3;Dynamicity;409
11.4.2.4;Affectivity;409
11.4.2.5;Developmental Auditory Synesthesias;409
11.4.2.5.1;Auditory-visual Synesthesia;409
11.4.2.5.2;Auditory-olfactory and auditory-gustatory Synesthesia;412
11.4.2.5.2.1;Auditory Synesthesia With Auditory Concurrent (Table 22.4);413
11.4.2.5.2.2;Bidirectional Auditory Synesthesia;413
11.4.2.5.2.3;Prevalence and Genetics of Developmental Synesthesias;413
11.4.2.5.2.4;Neurobiologic Investigation of Developmental Auditory Synesthesias;413
11.4.2.5.3;Structural Studies;413
11.4.2.5.4;Functional Studies;414
11.4.2.5.5;Neurophysiologic Studies;414
11.4.2.5.5.1;Neural Models of Developmental Synesthesias;416
11.4.2.6;Acquired Auditory Synesthesias;418
11.4.2.6.1;Acquired Auditory-visual Synesthesia;418
11.4.2.6.2;Lesional Acquired auditory-visual Synesthesia;418
11.4.2.6.2.1;Lesional Acquired auditory-visual Synesthesia With Pathological Affection of Anterior Optic Pathways (i.e., Visual Deaffer...;418
11.4.2.6.2.2;Neurophysiologic Investigations;419
11.4.2.6.2.3;Lesional auditory-visual Synesthesia Associated With Pathological Affection of the Central Nervous System With Intact Visua...;420
11.4.2.6.3;Non-lesional auditory-visual Synesthesia;420
11.4.2.6.3.1;Non-lesional auditory-visual Synesthesia Associated With Epilepsy;420
11.4.2.6.3.2;Non-lesional auditory-visual Synesthesia Associated With Migraines;420
11.4.2.6.3.3;Idiopathic non-lesional auditory-visual Synesthesia;420
11.4.2.6.3.3.1;Mechanisms of Acquired Auditory-visual Synesthesia;420
11.4.2.6.3.3.2;Acquired Auditory-tactile Synesthesia;422
11.4.2.7;Induced Synesthesias;422
11.4.2.7.1;Auditory Synesthesia Induced by Sensory Deprivation;422
11.4.2.7.2;Drug-induced Auditory Synesthesia (Use of Hallucinogens and Psychedelics);422
11.4.2.7.3;Mechanism of Induced Auditory Synesthesias;423
11.4.3;Effect of Drugs on Developmental Synesthesia;423
11.4.4;Auditory Synesthesia: History and art;423
11.4.5;Conclusion;424
11.4.6;References;424
11.5;Chapter 23: Tinnitus;428
11.5.1;Introduction;428
11.5.2;Determining Tinnitus Etiology;428
11.5.2.1;Specific Quality;428
11.5.2.1.1;Specific and Always Lateralized;428
11.5.2.1.2;Sudden, Brief, Unilateral, Tapering Tinnitus (SBUTT);428
11.5.2.1.3;Coarse Intermittent Sounds Coincident With Jaw Or head Movements;429
11.5.2.1.4;Fluttering;429
11.5.2.1.4.1;Specific and Always Non-lateralized;429
11.5.2.1.5;Exploding-head Syndrome;429
11.5.2.1.5.1;Specific and Sometimes, But Not Always, Unilateral;429
11.5.2.1.6;Autophony (echoing of the Voice), Or Blowing Tinnitus;429
11.5.2.1.7;Hallucinations (non-verbal, Stereotyped Repetitive);430
11.5.2.1.8;Clicking;430
11.5.2.1.8.1;Non-lateralized;430
11.5.2.1.8.2;Lateralized;430
11.5.2.1.8.2.1;Unilateral Staccato Irregular Intermittent (typewriter Tinnitus).;430
11.5.2.1.9;Pulsatile (cardiac Synchronous);431
11.5.2.1.9.1;Non-lateralized;431
11.5.2.1.9.2;Lateralized Or Non-lateralized: Somatosensory Pulsatile Tinnitus Syndrome;431
11.5.2.1.9.3;Lateralized;431
11.5.2.1.9.3.1;Eighth-nerve Vascular Compression.;432
11.5.2.2;Non-specific Quality;433
11.5.2.2.1;Always Non-lateralized;434
11.5.2.2.2;Chronic Progressive Symmetric Hearing Loss (presbycusis, Chronic Acoustic Trauma, Hereditary Hearing loss);434
11.5.2.2.3;Autoimmune inner-ear Disease;434
11.5.2.2.4;Central Nervous System Disorder – Rostral To trapezoid body;434
11.5.2.2.5;Medication-related (including Withdrawal Syndromes);434
11.5.2.2.5.1;Always Lateralized;435
11.5.2.2.6;Never With Vestibular Symptoms;435
11.5.2.2.6.1;Conductive Hearing loss;435
11.5.2.2.6.2;Otoacoustic Emissions;435
11.5.2.2.6.3;Eighth-nerve Compression (usually Vascular);435
11.5.2.2.7;May Be With Vestibular Symptoms;435
11.5.2.2.7.1;Ménière's Syndrome;435
11.5.2.2.8;Perilymphatic Fistula;435
11.5.2.2.9;Superior Semicircular Canal Dehiscence (SSCD);435
11.5.2.2.10;Herpes Zoster Oticus (Ramsay Hunt Syndrome);436
11.5.2.2.11;Cerebellopontine Angle Tumors;436
11.5.2.2.12;Central Nervous System Disorder – Caudal to Trapezoid body;436
11.5.2.2.13;Sudden Idiopathic Hearing loss;436
11.5.2.2.13.1;May or May Not Be Lateralized;436
11.5.2.2.14;Acute Acoustic Trauma;436
11.5.2.2.15;Somatic (head Or Upper Cervical);437
11.5.2.2.16;Head Trauma;438
11.5.2.2.17;Postinfectious;438
11.5.2.2.18;Idiopathic;438
11.5.3;Treatment of Tinnitus;438
11.5.4;Hyperacusis;439
11.5.5;The Neurology of Tinnitus;439
11.5.5.1;Hearing Loss and Somatic Tinnitus: the Unilateral Dorsal Cochlear Nucleus Hypothesis;439
11.5.5.1.1;Hearing Loss;439
11.5.5.1.2;The Somatosensory System;440
11.5.5.1.3;Why Does the Somatosensory System Communicate With the DCN?;442
11.5.5.1.4;Neck Proprioception;442
11.5.5.1.5;Jaw Proprioception;443
11.5.5.1.5.1;The Dorsal Cochlear Nucleus Hypothesis and Non-lateralized Tinnitus;443
11.5.5.1.5.2;Implications of the DCN Hypothesis;443
11.5.5.2;The Tinnitus Pathway Rostral To DCN;445
11.5.5.3;Tinnitus is a Threshold Phenomenon;445
11.5.5.4;Typewriter Tinnitus: cross-talk Between Auditory Nerve Fibers;446
11.5.6;Conclusions;446
11.5.7;References;447
11.6;Chapter 24: Auditory Hallucinations;452
11.6.1;Introduction;452
11.6.2;Definition, Conceptualization, and Classification;452
11.6.2.1;Definition;452
11.6.2.2;Conceptualization and Demarcation;453
11.6.2.3;Classification;453
11.6.3;Phenomenologic Characteristics;453
11.6.3.1;Perceived Location;453
11.6.3.1.1;Verbal Auditory Hallucinations;454
11.6.3.1.2;Non-verbal Auditory Hallucinations;455
11.6.3.1.3;Musical Hallucinations;455
11.6.4;Etiology;456
11.6.4.1;Occurrence in the Absence of Pathology;457
11.6.5;Pathophysiology;458
11.6.5.1;Evidence for a Functional Auditory Network;459
11.6.5.2;Evidence for a Structural Auditory Network;462
11.6.5.3;Pathophysiologic Processes;463
11.6.5.4;Pathophysiology of Musical Hallucinations;463
11.6.6;Treatment;464
11.6.6.1;Pharmacotherapy;464
11.6.6.2;Non-pharmacologic Treatment Methods;465
11.6.7;Metatheoretic Considerations;466
11.6.7.1;Insights From the Philosophy of Science;466
11.6.7.2;Insights From Network Science;468
11.6.8;Conclusion;469
11.6.9;References;471
11.7;Chapter 25: Palinacousis;476
11.7.1;Introduction;476
11.7.2;Defining Characteristics;476
11.7.2.1;Perseveration;476
11.7.2.2;Illusion;476
11.7.3;History;477
11.7.4;Anatomy;477
11.7.5;Auditory Memory;479
11.7.6;Clinical Characteristics of Palinacousis;479
11.7.6.1;Content;479
11.7.6.2;Quality;479
11.7.6.3;Latency;480
11.7.6.4;Lateralization Of sound;480
11.7.6.5;Lesion Location;480
11.7.7;Differential Diagnosis;480
11.7.7.1;Auditory Hallucinations of Psychotic Illness;480
11.7.7.2;Postictal Psychosis;482
11.7.7.3;Echolalia;482
11.7.7.4;Palilalia;483
11.7.7.5;Tinnitus;483
11.7.8;Pathophysiology of Palinacousis;483
11.7.8.1;Ictal;483
11.7.8.2;Postictal;484
11.7.9;Etiology;485
11.7.10;Associated Phenomena;485
11.7.10.1;Palinopsia;485
11.7.10.2;Music Hallucinations;485
11.7.11;Conclusions;485
11.7.12;References;485
11.8;Chapter 26: Musicogenic Epilepsy;488
11.8.1;Seizures and Reflex Epilepsies;488
11.8.2;Clinical Aspects of Musicogenic Seizures;489
11.8.3;Diagnostic Evaluation of Musicogenic Seizures;489
11.8.4;Illustrative case;490
11.8.5;Functional Imaging of Musicogenic Seizures;491
11.8.6;Relevance of Musicogenic Epilepsy to Epilepsy And music;493
11.8.7;Acknowledgments;495
11.8.8;References;495
11.9;Chapter 27: Deafness in Cochlear and Auditory Nerve Disorders;498
11.9.1;Introduction;498
11.9.2;Structures Affected By Sensorineural Hearing loss;498
11.9.2.1;Outer Hair cells;498
11.9.2.2;Inner Hair cells;498
11.9.2.3;Stria Vascularis;499
11.9.2.4;Auditory nerve;499
11.9.3;Etiology;500
11.9.3.1;Hereditary Causes;500
11.9.3.2;Noise;500
11.9.3.3;Ototoxic drugs;501
11.9.3.4;Hypoxia;501
11.9.3.5;Aging;501
11.9.4;Diagnosis;502
11.9.4.1;Threshold Measurement;502
11.9.4.2;Differentiating Damage to Structures In the cochlear and Auditory nerve;503
11.9.4.3;Otoacoustic Emissions;503
11.9.4.4;Diagnosing Auditory Nerve Dysfunction;503
11.9.5;The Effects of Sensorineural Hearing Loss on Auditory Coding;503
11.9.5.1;The Effects of Cochlear Damage On auditory coding;504
11.9.5.1.1;Rate Place Coding;504
11.9.5.1.2;Temporal Coding;504
11.9.5.2;The Effects of Auditory Nerve Damage On auditory Coding;505
11.9.6;Perceptual Consequences of Sensorineural Hearing loss;505
11.9.6.1;Perceptual Consequences of Cochlear Damage;505
11.9.6.1.1;Loudness Perception;505
11.9.6.1.2;Frequency and Pitch Perception;506
11.9.6.1.3;Poor Frequency Selectivity;507
11.9.6.1.4;Poor Temporal Coding;507
11.9.6.1.5;Spatial Hearing;507
11.9.6.1.6;Binaural Unmasking;508
11.9.6.1.7;Speech Perception;508
11.9.7;Treatment of Sensorineural Hearing loss;509
11.9.7.1;Hearing aids;509
11.9.7.2;Cochlear Implants;510
11.9.8;Summary;510
11.9.9;References;510
11.10;Chapter 28: Auditory Neuropathy;514
11.10.1;Introduction;514
11.10.2;Diagnosis;515
11.10.2.1;Electrophysiologic Procedures;515
11.10.2.1.1;Auditory Cortical Potentials;516
11.10.2.2;Neuroimaging;518
11.10.2.3;Audiology and Psychoacoustics;518
11.10.2.3.1;Audiologic Measures;518
11.10.3;Etiology;519
11.10.4;Pathologies of Auditory Neuropathy;519
11.10.4.1;Auditory nerve;519
11.10.4.1.1;Auditory Nerve Damage Accompanying Acoustic Trauma;520
11.10.4.1.2;Inner Hair Cell Ribbon Synapses;520
11.10.5;Clinical Expression of Auditory Neuropathy;520
11.10.6;Hearing Disorders Accompanying Auditory Neuropathy;521
11.10.6.1;Sound Detection Thresholds;521
11.10.6.2;Speech Perception;521
11.10.7;Auditory Processing in Auditory Neuropathy;522
11.10.8;Treatment of Auditory Neuropathy;523
11.10.8.1;Signal Clarity;523
11.10.8.2;Amplification (hearing aid);523
11.10.8.3;Cochlear Electric Implants;524
11.10.9;New Directions;524
11.10.10;References;524
11.11;Chapter 29: Hearing Disorders in Brainstem Lesions;528
11.11.1;Introduction;528
11.11.2;Brainstem Auditory System;528
11.11.3;Prevalence of Hearing Disorders in Brainstem Diseases;529
11.11.4;Evaluation of brainstem-related Hearing Disorders;530
11.11.4.1;Psychoacoustic Testing;531
11.11.4.1.1;Patients With Brainstem Disorders Without Auditory Complaints;532
11.11.4.1.2;Patients With Brainstem Disorders and Hearing Loss;532
11.11.4.2;Neuroimaging;533
11.11.4.3;Brainstem Auditory Evoked Potentials;534
11.11.5;Hearing Abnormalities in Isolated Lesions of Auditory Brainstem Centers;535
11.11.5.1;Disorders Limited to the Auditory nerve;535
11.11.5.2;Unilateral Lesions of the Cochlear Nuclei;535
11.11.5.3;Unilateral Lesions of the Superior Olivary Complex;535
11.11.5.4;Unilateral Lesions of the Lateral Lemniscus;535
11.11.5.5;Unilateral Lesions of the Trapezoid body;537
11.11.5.6;Unilateral Lesions to the Inferior Colliculus;537
11.11.5.7;Isolated Bilateral Lesion of the Inferior Colliculi;539
11.11.5.8;Isolated Bilateral Lesion of Pontomedullary Region;540
11.11.6;Auditory Hallucinations in Brainstem Disorders;540
11.11.7;Brainstem Clinical Disorders;544
11.11.7.1;Vestibular Schwannomas and Cerebellopontine Angle Tumors;544
11.11.7.1.1;Symptomatology;544
11.11.7.1.2;Audiometry and Other Diagnostic Testing;546
11.11.7.1.3;Physiopathology;547
11.11.7.1.4;Neuroimaging;547
11.11.7.1.5;Neurofibromatosis Type 2 (NF2);548
11.11.7.1.6;Treatment Modalities;548
11.11.7.2;Brainstem Strokes Affecting the Auditory System;548
11.11.7.2.1;Occlusion of the Internal Auditory Artery;548
11.11.7.2.2;The Lateral Inferior Pontine Syndrome;549
11.11.7.2.3;The Lateral Superior Pontine Syndrome;550
11.11.7.3;Multiple Sclerosis Hearing Abnormalities;550
11.11.8;Management of Brainstem Hearing Disorders;550
11.11.9;References;550
11.12;Chapter 30: Central Auditory Processing Disorders in Children and Adults;556
11.12.1;Introduction;556
11.12.2;Current Definitions and Conceptualizations Of CAPD;556
11.12.2.1;Relationship of CAPD to Language, Learning, and Communication;559
11.12.3;Diagnosis Of CAPD;561
11.12.3.1;Behavioral Tests for CAPD Diagnosis;561
11.12.3.1.1;Dichotic Speech Tests;562
11.12.3.1.2;Temporal Processing Tests;562
11.12.3.1.3;Monaural Low-redundancy Speech Tests;562
11.12.3.1.4;Binaural Interaction Tests;562
11.12.3.1.5;Auditory Discrimination Tests;562
11.12.3.2;Selection of Behavioral Central Auditory tests;562
11.12.3.3;Interpretation of Behavioral Central Auditory tests;565
11.12.3.4;Electrophysiologic Tests for CAPD Diagnosis;566
11.12.4;Intervention For CAPD;567
11.12.4.1;Environmental Modifications;567
11.12.4.2;Central Resources Training;567
11.12.4.3;Direct Remediation;569
11.12.5;Case study;570
11.12.6;Conclusions;571
11.12.7;References;572
11.13;Chapter 31: Auditory Neglect and Related Disorders;576
11.13.1;Introduction;576
11.13.1.1;Clinical Presentation of Neglect;576
11.13.1.2;Extinction;577
11.13.2;Auditory Behavioral Deficits in Neglect and Similar Disorders;577
11.13.2.1;Auditory Extinction;577
11.13.2.2;Auditory Extinction in Dichotic Speech tests;578
11.13.2.3;Extinction and Temporal order;580
11.13.2.4;Target Detection tasks;580
11.13.2.5;Non-spatial Auditory Deficits in Neglect;581
11.13.2.6;Alloacusis;582
11.13.2.7;Sound Lateralization;582
11.13.2.8;Other Deficits of Spatial Hearing;583
11.13.3;Neural Basis of Neglect;584
11.13.3.1;Lesion sites;584
11.13.3.2;Models of Neglect;584
11.13.3.3;Functional Imaging;584
11.13.4;Conclusion;586
11.13.4.1;What is Auditory Neglect?;586
11.13.4.2;Which Workup Should Be used?;586
11.13.4.3;Can Auditory Neglect Be Treated?;587
11.13.4.4;Open Questions;587
11.13.5;Acknowledgments;588
11.13.6;References;588
11.14;Chapter 32: Auditory Agnosia;592
11.14.1;Introduction;592
11.14.2;Definitions;592
11.14.3;General Auditory Agnosia;595
11.14.4;Verbal Auditory Agnosia (word deafness);595
11.14.4.1;Apperceptive Verbal Auditory Agnosia;597
11.14.4.2;Associative Verbal Auditory Agnosia;598
11.14.5;Phonagnosia;599
11.14.6;Agnosia for Environmental Sounds;599
11.14.7;Amusia;600
11.14.8;Auditory Affective Agnosia;600
11.14.9;Treatment for Auditory Agnosia;601
11.14.10;Conclusion;602
11.14.11;References;602
11.15;Chapter 33: Congenital Amusias;608
11.15.1;Introduction;608
11.15.2;A Deficit on the Pitch Dimension: Perception and Memory;610
11.15.2.1;Pitch Perception;610
11.15.2.2;Memory For pitch;611
11.15.3;Neural Correlates of Congenital Amusia: Anatomic and Functional data;612
11.15.3.1;Anatomic Correlates;612
11.15.3.2;Functional Investigations;614
11.15.4;Are the Processing Deficits in Congenital Amusia pitch-specific?;615
11.15.4.1;Testing Amusics Processing of the Time Dimension in Music, of Language, and Of space;615
11.15.4.2;Temporal Processing;615
11.15.4.3;Speech Processing;615
11.15.4.4;Space Processing;617
11.15.5;Disorders of Pitch Production and Music Production in Congenital Amusia: a Dissociation From Perception?;617
11.15.6;Implicit Pitch Processing in Congenital Amusia;619
11.15.7;Conclusion;620
11.15.8;References;621
11.16;Chapter 34: Acquired Amusia;626
11.16.1;Introduction;626
11.16.2;Scope of This Chapter;627
11.16.3;A Cognitive Framework for Understanding and Assessing Amusia;629
11.16.4;Disorders of Musical Scene Analysis;632
11.16.5;Disorders of Musical Property Encoding;632
11.16.5.1;Disorders of Pitch Perception;632
11.16.5.2;Disorders of Temporal Perception;635
11.16.5.3;Disorders of Timbre Perception;637
11.16.6;Disorders of Musical Object Perception: Apperceptive Agnosia;638
11.16.7;Disorders of Musical Object Recognition: Associative Agnosias;639
11.16.7.1;Disorders of Melody Recognition;639
11.16.7.2;Disorders of Musical Instrument Sound Recognition;641
11.16.8;Disorders of Musical Emotion Processing;641
11.16.9;Conclusions and Future Directions;644
11.16.10;Acknowledgments;645
11.16.11;References;645
11.17;Chapter 35: Hearing Disorders in Stroke;652
11.17.1;Introduction;652
11.17.1.1;Blood Supply of the Auditory System;652
11.17.1.2;Hearing Disorders in Stroke Sufferers;653
11.17.2;Hearing Loss After Stroke;653
11.17.2.1;Hearing Loss and Stroke in Population Studies;653
11.17.2.2;Sudden-onset Hearing Loss Due to Ischemic Stroke of the Vertebrobasilar Territory;654
11.17.2.3;Sudden Hearing Loss After Ischemic Stroke of the Upper Brainstem and Midbrain;655
11.17.2.4;Sudden Hearing Loss After Hemorrhagic Lesions Affecting the Vertebrobasilar Territory;655
11.17.2.5;``Central´´ or ``cortical´´ Deafness;656
11.17.3;Auditory-processing Deficits After Stroke;660
11.17.4;Other Auditory Phenomena: Tinnitus, Auditory Hallucinations, Hyperacusis, and Palinacousis;661
11.17.5;Conclusions;663
11.17.5.1;Auditory Symptoms and Deficits After Stroke: Comments on Current Practice;663
11.17.5.2;Assessment of Auditory Function After Stroke: what Should We Do And why?;664
11.17.6;References;664
11.18;Chapter 36: Hearing Disorders in Multiple Sclerosis;668
11.18.1;Introduction;668
11.18.2;Protocol for Detecting Lesions in the Brainstem Auditory Pathway;668
11.18.3;Psychophysical Hearing Assessment;669
11.18.3.1;Pure-tone Threshold;669
11.18.3.2;Speech Intelligibility;670
11.18.3.3;Binaural Hearing;671
11.18.3.4;Interaural Discrimination tests;671
11.18.3.5;Binaural masking-level Difference;674
11.18.3.6;Lateralization Experiments;674
11.18.3.7;Correlation Between BAEP and Binaural Performances;676
11.18.4;Theoretic Explanations;677
11.18.4.1;Correlation Between MS and Audiologic tests;677
11.18.4.2;Model for Lateralization tasks;678
11.18.4.3;Correlation Between BAEP and Binaural Discrimination tasks;679
11.18.5;Conclusion;682
11.18.6;References;682
11.19;Chapter 37: Hearing and Music in Dementia;686
11.19.1;Introduction;686
11.19.2;Overview of Dementia;686
11.19.3;Hearing Function in Neurodegenerative Diseases;687
11.19.3.1;Hearing Impairment;687
11.19.3.2;Peripheral Auditory System Function;688
11.19.3.3;Central Auditory System;688
11.19.4;Processing of Music in Neurodegenerative Diseases;690
11.19.4.1;Framework for Examining Music Perception in Neurodegenerative Diseases;690
11.19.4.2;Alzheimer Disease;692
11.19.4.3;Frontotemporal Dementia;695
11.19.4.4;Parkinson's Disease;696
11.19.4.5;Huntington's Disease;697
11.19.4.6;Recognition of Emotions In music;697
11.19.5;Processing of non-verbal Sounds in Neurodegenerative Diseases;698
11.19.6;Music as Therapy for Dementia;701
11.19.7;Summary;702
11.19.8;References;702
11.20;Chapter 38: Future Advances;708
11.20.1;Introduction;708
11.20.2;New and Developing Technologies;708
11.20.3;New Technologies Enable New large-scale Research Projects;708
11.20.4;Applications to Disease;709
11.20.5;References;711
11.21;Index;712
Chapter 1 Auditory pathways
anatomy and physiology
James O. Pickles* Department of Physiology and Pharmacology, School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland, Australia
* Correspondence to: James O. Pickles, Department of Physiology and Pharmacology, School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland 4072, Qld, Australia. email address: j.pickles@uq.edu.au Abstract
This chapter outlines the anatomy and physiology of the auditory pathways. After a brief analysis of the external, middle ears, and cochlea, the responses of auditory nerve fibers are described. The central nervous system is analyzed in more detail. A scheme is provided to help understand the complex and multiple auditory pathways running through the brainstem. The multiple pathways are based on the need to preserve accurate timing while extracting complex spectral patterns in the auditory input. The auditory nerve fibers branch to give two pathways, a ventral sound-localizing stream, and a dorsal mainly pattern recognition stream, which innervate the different divisions of the cochlear nucleus. The outputs of the two streams, with their two types of analysis, are progressively combined in the inferior colliculus and onwards, to produce the representation of what can be called the “auditory objects” in the external world. The progressive extraction of critical features in the auditory stimulus in the different levels of the central auditory system, from cochlear nucleus to auditory cortex, is described. In addition, the auditory centrifugal system, running from cortex in multiple stages to the organ of Corti of the cochlea, is described. Keywords Hearing anatomy physiology cochlea cochlear nucleus superior olive inferior colliculus medial geniculate auditory cortex review Introduction and overview
The auditory brainstem, midbrain, and cortex have a multiplicity of parallel and overlapping pathways, which have parallel but overlapping and interrelated functions. In addition, the stages of analysis of the auditory signal are not as clearly separated or as clearly comprehensible as in for instance the visual system. It is difficult therefore to use a simple functional framework to help understand the anatomic and physiologic results. It is hoped that this chapter will provide a scheme by which the auditory system can be more easily approached and understood. The auditory signal is a time-dependent variation in sound pressure. From the one-dimensional stimuli as received by each ear, the whole multifeatured auditory world is constructed. Therefore the auditory system accomplishes an outstanding feat of both analysis and synthesis. This chapter will describe some of the anatomy and physiology that underlies this. The issues described in this chapter are also described in more detail in An Introduction to the Physiology of Hearing, to which the reader is referred for further information (Pickles, 2012). The outer and middle ears
The input impedance of the cochlea (defined as the pressure required to produce a unit displacement of the oval window) is some 200 times greater than that of free air (Nakajima et al., 2009). If the sound vibrations met the oval window directly, we can calculate that most of the energy would be reflected, with only 2% of the energy being transmitted. However, the outer and middle ears increase this transmission substantially. The increase in transmission is accomplished at two stages. Firstly, the outer ear acts as a directionally sensitive ear trumpet, collecting sound pressures over the area of the pinna, and by a set of resonances, increasing the sound pressure at the rather smaller tympanic membrane. The frequency peaks of the major resonances are complementary, so that the pressure at the eardrum is raised relatively uniformly, by 15–20 dB, over the frequency range from 2 to 8 kHz, with transmission being similarly raised. Secondly, there is an impedance transformer in the middle ear; this stage makes the major contribution. The middle-ear transformer has two components. Firstly, the largest factor arises from the ratio of the area of the tympanic membrane to the area of the footplate of the stapes in the oval window. The two areas are 60 mm2 and 3.2 mm2 respectively. The pressure on the oval window, and hence the pressure/displacement ratio, is therefore increased 60/3.2 = 18.75 times. The second factor is the lever action: the arm of the malleus (i.e., the umbo) is 2.1 times longer than the arm of the stapes. Therefore the force at the round window, and hence the pressure, is increased 2.1 times, while the displacement is decreased 2.1 times. The impedance ratio, being pressure/displacement, is therefore increased 2.12 = 4.4 times. The overall impedance change of the driving stimulus is therefore increased by 18.75 × 4.4 times = 82.5 times. The overall effect of the outer and middle ears is to increase the transmission efficiency, at its optimum frequency of 1 kHz, to 35% (Rosowski, 1991). Most of the losses in transmission are due to friction in the middle ear. The absolute threshold and relation to outer- and middle-ear transmission
Over a wide range of frequencies, and in a variety of mammals, including human beings, the auditory absolute threshold corresponds to a power of the order of 10–18 W absorbed by the inner ear (Rosowski, 1991). Since at threshold we integrate energy for approximately 300 ms to make a decision, this equals an energy detection threshold of 3 × 10–19 J. This corresponds to the energy in a single quantum of red light. Therefore the fundamental energy sensitivities of the eye and the ear are comparable. In young human beings with good hearing, the threshold of 10–18 W delivered to the cochlea applies over the range of 450 Hz to at least 10 kHz. Therefore, within this range the shape of the audiogram, i.e., the variation in the threshold of hearing as a function of frequency, can be described by the variation in the efficiency of transmission through the outer and middle ears to the inner ear. At higher and lower frequencies, however, other factors come into play. The upper frequency limit of hearing in human beings is commonly taken as 20 kHz in young children and 15 kHz in young adults (e.g., Dadson and King, 1952). The upper frequency limit of hearing arises because the cochlea itself becomes unresponsive to stimuli of higher frequency (Ruggero and Temchin, 2002). At low frequencies (< 1 kHz), the threshold rises gradually as the stimulus frequency is lowered, so there is no clear lower frequency limit of hearing. The gradually increasing threshold arises because below 1 kHz there is reduced transmission of power through the middle ear, and at still lower frequencies (< 450 Hz), the traveling wave reaches the apex of the cochlea. In this case, some of the power is shunted through the helicotrema, an opening between the scala vestibuli and the scala tympani at the extreme apex of the cochlea, and is not able to activate the hair cells. The cochlea
Overall anatomy
The cochlea is a spiral fluid-filled tube, with (in human beings) 2.5 turns, an overall width of 1 cm, and standing 5 mm high. It is unfortunate that, following the well-known illustrations of Netter (1948), many common illustrations show the cochlea at about three times this size. The fluid-filled tube has three divisions or scalae, which spiral together around the central core, the modiolus, containing the auditory nerve and many of the blood vessels. One membrane between the scalae, the basilar membrane, contains the organ of Corti, the site of the receptor cells (Fig. 1.1). The spiral allows a long (35 mm long) basilar membrane and organ of Corti to be packed into a small overall dimension. Fig. 1.1 Cross-section of the organ of Corti, as it appears in the basal turn, showing the hair cells in the reticular lamina, with their bundles of stereocilia running to the tectorial membrane. Deiters’ cells send extensions (phalanges) up to the reticular lamina, running in the spaces around the outer hair cells, although the phalanges are incompletely shown in this particular cross-section. The modiolus is to the left of the figure. (Reproduced rom Pickles, 2013.) Anatomy in relation to function
The cochlea performs an amazing feat of sound detection and analysis. The absolute threshold mentioned above is many times lower than the thermal noise expected in the detector. Moreover, the cochlea performs a frequency analysis with a high degree of resolution, but without the long temporal “ringing” that would normally accompany such a high degree of frequency resolution. The input vibrations of the cochlea produce the well-known traveling wave on the basilar membrane, which peaks more basally for stimuli of higher frequencies, and more apically for stimuli of lower frequencies (Fig. 1.2A). Therefore stimulus frequency is mapped on to place of stimulation in the cochlea. As originally measured by Békésy in human cadavers (see Békésy, 1960), the traveling wave was relatively small and...
