Hearing. Anatomy, Physiology and Disorders of the Auditory System

325 Pages·2006·0.45 MB·English

by  Aage R. Moller

HEARING:
ANATOMY, PHYSIOLOGY,
AND DISORDERS OF THE
AUDITORY SYSTEM
Second Edition
This page intentionally left blank
HEARING:
ANATOMY,
PHYSIOLOGY, AND
DISORDERS OF THE
AUDITORY SYSTEM
Second Edition
A. R. Møller
School of Behavioral and Brain Sciences
University of Texas at Dallas
Texas
AMSTERDAM • BOSTON • HEIDELBERG • LONDON
NEW YORK • OXFORD • PARIS • SAN DIEGO
SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO
Academic Press is an imprint of Elsevier
Academic Press is an imprint of Elsevier
30 Corporate Drive, Suite 400, Burlington, MA01803, USA
525 B Street, Suite 1900, San Diego, California 92101-4495, USA
84 Theobald’s Road, London WC1X 8RR, UK
This book is printed on acid-free paper.
Copyright © 2006, 2000 Elsevier Inc. All rights reserved.
No part of this publication may be reproduced or transmitted in any form or by
any means, electronic or mechanical, including photocopy, recording, or any
information storage and retrieval system, without permission in writing from
the publisher.
Permissions may be sought directly from Elsevier’s Science & Technology Rights
Department in Oxford, UK: phone: [phone], fax: [phone],
E-mail: [email protected]. You may also complete your request on-line via
the Elsevier homepage (http://elsevier.com), by selecting “Support & Contact”
then “Copyright and Permission” and then “Obtaining Permissions.”
Front cover design concept by Milda Dorsett.
Library of Congress Cataloging-in-Publication Data
Møller, Aage R.
Hearing : anatomy, physiology, and disorders of the auditory system/A.R.
Moller, -- 2nd ed.
p. cm.
Includes bibliographical references and index.
ISBN-13: 978-0-12-372519-6 (casebound : alk. paper)
ISBN-10: 0-12-372519-4 (casebound : alk. paper)
1. Hearing--Physiological aspects. 2. Hearing disorders--Pathophysiology.
3. Ear--Anatomy. I. Title.
RF290.M58 2006
617.8--dc22 2006014244
British Library Cataloguing-in-Publication Data
Acatalogue record for this book is available from the British Library.
ISBN 13: 978-0-12-372519-6
ISBN 10: 0-12-372519-4
For information on all Academic Press publications
visit our Web site at www.books.elsevier.com
Printed in the United States of America
06 07 08 09 10 11 9 8 7 6 5 4 3 2 1
Contents
Preface ix 4. Middle Ear 22
Acknowledgements xi 4.1. Middle Ear as an Impedance
Introduction xiii Transformer 24
4.2. Transfer Function of the Human
Middle Ear 27
S E C T I O N
4.3. Impulse Response of the Human
I Middle Ear 29
4.4. Linearity of the Middle Ear 29
THE EAR 4.5. Acoustic Impedance of the Ear 29
4.6. Contributions of Individual Parts of the
Middle Ear to Its Impedance 32
CHAPTER 1
Anatomy of the Ear
1. Abstract 3 CHAPTER 3
2. Introduction 3 Physiology of the Cochlea
3. Outer Ear 3 1. Abstract 41
3.1. Ear Canal 5 2. Introduction 41
4. Middle Ear 6 3. Frequency Selectivity of the Basilar
4.1. Tympanic Membrane 6 Membrane 42
4.2. Ossicles 8 3.1. Traveling Wave Motion 43
4.3. Middle-ear Muscles 8 3.2. Basilar Membrane Frequency Tuning
4.4. Eustachian Tube 8 Is Non-linear 44
4.5. Middle-ear Cavities 9 3.3. Frequency Tuning of the Basilar
5. Cochlea 10 Membrane 45
5.1. Organ of Corti 10 3.4. Role of the Outer Hair Cells in Basilar
5.2. Basilar Membrane 13 Membrane Motion 46
5.3. Innervation of Hair Cells 13 3.5. Epochs of Research in Cochlear
5.4. Fluid Systems of the Cochlea 15 Mechanics 47
5.5. Blood Supply to the Cochlea 16 4. Sensory Transduction in the Cochlea 48
4.1. Excitation of Hair Cells 48
4.2. Which Phase of a Sound Excites Hair Cells
CHAPTER 2 (Rarefaction or Condensation)? 48
Sound Conduction to the Cochlea 4.3. Molecular Basis for Sensory
1. Abstract 19 Transduction 50
2. Introduction 19 4.4. Endocochlear Potential 52
3. Head, Outer Ear and Ear Canal 20 4.5. Cochlea as a Generator of Sound 53
3.1. Ear Canal 20 4.6. Efferent Control of Hair Cells 55
3.2. Head 20 4.7. Autonomic Control of the Cochlea 55
3.3. Physical Basis for Directional Hearing 21 5. Autoregulation of Blood Flow to the Cochlea 56
v
vi Contents
CHAPTER 4 3.3. Cochlear Non-linearity Is Reflected in
Sound Evoked Electrical Potentials Frequency Selectivity of Auditory Nerve
in the Cochlea Fibers 99
3.4. Frequency Tuning in Nuclei of the
1. Abstract 57
Ascending Auditory Pathways 102
2. Introduction 57
3.5. Tonotopic Organization in the Nuclei of the
3. Electrical Potentials in the Cochlea 57
Ascending Auditory Pathways 104
3.1. Cochlear Microphonics 58
3.6. Extraction of Information from Place
3.2. Summating Potential 59
Coding of Frequency 106
3.3. Action Potential 59
4. Coding of Temporal Features 106
3.4. Electrocochleographic Potentials 64
4.1. Coding of Periodic Sounds 107
Section I References 68
4.2. Extraction of Information from the
Temporal Pattern of Neural Discharges 111
S E C T I O N 5. Is Temporal or Place Code the Basis for
II Discrimination of Frequency? 112
5.1. Temporal Hypothesis for Frequency
Discrimination of Complex Sounds 112
THE AUDITORY NERVOUS SYSTEM
5.2. Place Hypothesis for Frequency
Discrimination of Complex Sounds 113
5.3. Preservation of the Temporal Code of
CHAPTER 5
Frequency 115
Anatomy of the Auditory Nervous System
5.4. Preservation of the Place Code 117
1. Abstract 75
5.5. Robustness of the Temporal Code 117
2. Introduction 76
5.6. Robustness of the Place Code of
3. Classical Ascending Auditory Pathways 76
Frequency 117
3.1. Auditory Nerve 76
5.7. Coding of Speech Sounds 117
3.2. Cochlear Nucleus 80
5.8. ADuplex Hypothesis of Frequency
3.3. Superior Olivary Complex 81
Discrimination 118
3.4. Lateral Lemniscus and Its Nuclei 81
5.9. Cochlear Spectral Filtering May Be
3.5. Inferior Colliculus 81
Important in other Ways than Frequency
3.6. Medial Geniculate Body 81
Discrimination 118
3.7. Auditory Cerebral Cortex 82
5.10. Speech Discrimination on Spectral
3.8. Differences between the Classical Auditory
Information Only 118
Pathways in Humans and in Animals 84
5.11. Conclusion 119
4. Non-classical Ascending Auditory Pathways 85
6. Coding of Complex Sounds 119
5. Parallel Processing and Stream Segregation 87
6.1. Response to Tone Bursts 120
5.1. Parallel Processing 88
6.2. Coding of Small Changes in
5.2 Stream Segregation 88
Amplitude 121
5.3. Connections to Non-auditory Parts of the
6.3. Response to Tones with Changing
Brain 89
Frequency 128
6. Descending Pathways 89
6.4. Selectivity to Other Temporal Patterns
of Sounds 138
6.5. Coding of Sound Intensity 140
CHAPTER 6 6.6. Conclusion 140
Physiology of the Auditory Nervous
7. Directional Hearing 142
System 7.1. Physical Basis for Directional Hearing 142
1. Abstract 93 7.2. Neurophysiologic Basis for Sound
2. Introduction 94 Localization 143
3. Representation of Frequency in the Auditory 7.3. Localization in the Vertical Plane 146
Nervous System 95 7.4. Representation of Auditory Space
3.1 Hypotheses about Discrimination (Maps) 146
of Frequency 95 8. Efferent System 149
3.2. Frequency Selectivity in the Auditory 9. Non-classical Pathways 149
Nervous System 97 10. Effect of Anesthesia 150
Contents vii
CHAPTER 7 3. Pathologies of the Sound Conducting
Evoked Potentials from the Nervous Apparatus 206
System 3.1. Ear Canal 207
3.2. Middle Ear 207
1. Abstract 151
3.3. Impairment of Sound Conduction in the
2. Introduction 152
Cochlea 213
3. Near-field Potentials from the Auditory
3.4. Accuracy of Measurements of Conductive
Nervous System 152
Hearing Loss 213
3.1. Recordings from the Auditory Nerve 152
3.5. Implications of Impairment of Conduction
3.2. Recordings from the Cochlear
of Sound to the Cochlea 214
Nucleus 160
4. Pathologies of the Cochlea 215
3.3. Recordings from More Central Parts of the
4.1. General Audiometric Signs of Cochlear
Ascending Auditory Pathways 163
Pathologies 215
4. Far-field Auditory Evoked Potentials 163
4.2. Age-related Hearing Loss (Presbycusis) 216
4.1. Auditory Brainstem Responses 165
4.3. Noise Induced Hearing Loss 219
4.2. Middle Latency Responses 175
4.4. Implications of Hearing Loss on Central
4.3. Far-field Frequency Following Responses
Auditory Processing 226
in Humans 176
4.5. Modification of Noise Induced Hearing
4.4. Myogenic Auditory Evoked Potentials 177
Loss 226
4.6. Hearing Loss Caused by Ototoxic Agents
(Drugs) 227
CHAPTER 8
4.7. Diseases that Affect the Function of the
Acoustic Middle-ear Reflex
Cochlea 229
1. Abstract 181
4.8. Congenital Hearing Impairment 233
2. Introduction 181
4.9. Infectious Diseases 234
3. Neural Pathways of the Acoustic Middle-ear
4.10. Perilymphatic Fistulae 234
Reflex 182
4.11. Changes in Blood Flow in the Cochlea 234
4. Physiology 183
4.12. Injuries to the Cochlea from Trauma 234
4.1. Responses to Stimulation with Tones 184
4.13. Sudden Hearing Loss 234
4.2. Functional Importance of the Acoustic
5. Implications of Hearing Loss on Central Auditory
Middle-ear Reflex 187
Processing 235
4.3. Non-acoustic Ways to Elicit Contraction of the
5.1 Neural Components of Hearing Loss 236
Middle-ear Muscles 190
5.2. Role of Expression of Neural Plasticity 237
4.4. Stapedius Contraction May Be Elicited before
6. Pathologies from Damage to the Auditory
Vocalization 190
System 239
5. Clinical Use of the Acoustic Middle-ear Reflex 190
6.1. Auditory Nerve 239
Section II References 192
6.2. Other Space-occupying Lesions 243
7. Pathologies of the Central Auditory Nervous
System 243
S E C T I O N
7.1. Disorders of the Brainstem Auditory
III Pathways 244
7.2. Auditory Cortices 244
DISORDERS OF THE AUDITORY 7.3. Efferent System 246
7.4. Pathologies that Can Affect Binaural
SYSTEM AND THEIR
Hearing 246
PATHOPHYSIOLOGY
7.5. Viral Infections 246
7.6. Ototoxic Drugs 247
7.7. Sudden Hearing Loss 247
CHAPTER 9 8. Role of Neural Plasticity in Disorders of the
Hearing Impairment Central Auditory Nervous System 247
1. Abstract 205 8.1. What Is Neural Plasticity? 247
2. Introduction 206 8.2. What Can Initiate Expression of Neural
Plasticity? 250
viii Contents
CHAPTER 10 3.1. Function and Design of Auditory
Hyperactive Disorders of the Auditory Brainstem Implants 277
System 3.2. Physiological Basis for Auditory Brainstem
Implants 277
1. Abstract 253
3.3. Success of Auditory Brainstem Implants 278
2. Introduction 253
3.4. Patient Selection for Auditory Brainstem
3. Subjective Tinnitus 254
Implants 279
3.1. Assessment of Tinnitus 254
4. Role of Neural Plasticity 279
3.2. Disorders in which Tinnitus Is
Section III References 280
Frequent 255
3.3. Causes of Subjective Tinnitus and Other
Hyperactive Symptoms 255
APPENDIX A
3.4. Role of Expression of Neural Plasticity
Definitions in Anatomy 289
in Tinnitus 259
4. Abnormal Perception of Sounds 260
4.1. Hyperacusis 261
4.2. Phonophobia 262 APPENDIX B
4.3. Misophonia 262 Hearing Conservation Programs 291
4.4. Recruitment of Loudness 262 1. Introduction 291
5. Treatment of Subjective Tinnitus 263 2. Purpose and Design of Hearing Conservation
5.1. Medical Treatment 264 Programs 292
5.2. Electrical Stimulation 264 2.1. Basis for Hearing Conservation Programs 292
5.3. Surgical Treatment 265 3. Establishment of Noise Standards 295
5.4. Desensitization 266 3.1. Noise Level and Exposure Time 296
6. Treatment of Hyperacusis 266 3.2. Effect of Age-related Hearing Loss 296
3.3. What Degree of Hearing Loss is
Acceptable? 296
CHAPTER 11 4. Measurement of Noise 297
Cochlear and Brainstem Implants 4.1. Sound Level Meters 297
1. Introduction 267 4.2. Noise Dosimeters 298
2. Cochlear Implants 268 5. Personal Protection 299
2.1. Development of Cochlear Implants 268 5.1. Earplugs and Earmuffs 299
2.2. Function and Design of Cochlear 5.2. Active Noise Cancellation 300
Implants 268 5.3. Other Means of Reducing the Risk of Noise
2.3. Physiological Basis for Cochlear Implants 273 Induced Hearing Loss 300
2.4. Coding of Sound Intensity 275 6. Non-occupational Noise Exposure 300
2.5. Functions that Are Not Covered by Modern 7. Effect of Noise on Bodily Functions 300
Cochlear Implants 275 7.1. Effect of Ultrasound and Infrasound 300
2.6. Success of Cochlear Implants 276 Appendices References 301
2.7. Selection Criteria for Cochlear Implant List of Abbreviations 303
Candidates 277 Index 305
3. Cochlear Nucleus Implants 277
Preface
This book is intended for otologists, audiologists, by Academic Press, and the second, Hearing: Its
neurologists and researchers in the field of hearing. The Physiology and Pathophysiology, published in 2000, also
book will also be of interest to psychologists and psy- by Academic Press.
chiatrists who treat patients with tinnitus and other The book has 11 chapters that are organized in three
hyperactive auditory disorders. The book provides the sections. Chapters from earlier editions have been
basis for a broad understanding of the anatomy and re-organized and most parts have been re-written and
function of the ear and the auditory nervous system, new information has been added. Aseparate chapter
and it discusses the cause and treatment of hearing is devoted to an extended coverage of hyperactive
disorders. Most books on hearing focus either on the disorders, most importantly tinnitus, the cause and
anatomy and function of the ear, the auditory nervous treatment of which is discussed in detail. Anew chap-
system or on peripheral or central hearing disorders. ter describes cochlear and brainstem implants and
This book covers both anatomy and physiology of the hearing conservation programs are discussed in an
ear and the nervous system. The book also provides a appendix.
comprehensive coverage of disorders of the auditory The four chapters of Section I cover anatomy and
system emphasizing the interaction between patholo- physiology of the middle ear and the cochlea, includ-
gies of the middle ear and the cochlea and the function ing a chapter on the electrical potentials that are gen-
of the nervous system and vice versa. Hyperactive dis- erated by the cochlea. Section II has two chapters that
orders of the auditory nervous system and the role of cover anatomy and physiology of the nervous system.
expression of neural plasticity in causing auditory Both the classical and the less known non-classical
symptoms are also topics of the book. An extensive list (extralemniscal) auditory pathways are covered exten-
of references makes it possible for the reader to find sively. The latter is involved in some forms of tinnitus
original work on the different subjects. and may be activated in other disorders also. Athird
Understanding of the anatomy and the function of chapter is devoted to evoked potentials from the nerv-
the auditory system together with knowledge about ous system. The neural generators of the ABR are dis-
the pathophysiology of the auditory system are essen- cussed in detail. The anatomy and physiology of the
tial for all clinicians who are involved in diagnosis and acoustic middle-ear reflex is covered in a fourth chapter
treatment of disorders of the auditory system. The in this section.
book prepares the clinician and the clinical researcher The final section (Section III) discusses disorders of
for the challenges of the modern clinical auditory disci- the auditory system. Two chapters regard hearing
pline. The book also provides basic information about impairment and hyperactive disorders, focusing on tin-
the auditory system in a form that is suitable for the sci- nitus, its etiology, and treatment. These two chapters
entist who does basic research on the auditory system. stress the role of expression of neural plasticity. Athird
The book thus aims at cross-fertilization between clini- chapter in this section concerns cochlear implants and
cians, clinical researchers and basic scientists. It is my auditory brainstem implants. The basic design and
hope that such knowledge can guide basic auditory function of the processors in these modern auditory
research into clinically relevant questions. prostheses are described and the physiologic basis for
The book is the third edition of books on the auditory the function of these prostheses is discussed. An
system, the first, Auditory Physiology, published in 1983 appendix discusses hearing conservation programs.
ix