Front Cover

Hearing Loss

Copyright Page

Contents

Preface

List of Abbreviations

I. The Basics

1 Hearing Basics

1.1 Hearing Sensitivity in the Animal Kingdom

1.2 The Mammalian Middle Ear

1.3 The Mammalian Inner Ear

1.3.1 Basilar Membrane Mechanics

1.3.2 The Cochlear Amplifier

1.3.3 Mechanoelectrical Transduction

1.3.4 Cochlear Microphonics and Summating Potentials

1.3.5 Otoacoustic Emissions

1.4 The Auditory Nerve

1.4.1 Type I and Type II Nerve Fibers

1.4.2 Type I Responses

1.4.3 Compound Action Potentials

1.5 Ribbon Synapses

1.6 The Central Afferent System

1.6.1 Parallel Processing Between Cochlea and Inferior Colliculus

1.6.2 Parallel Processing Between IC and Auditory Cortex

1.6.2.1 Splitting up the Lemniscal Pathway

1.6.3 Parallel Processing in Auditory Cortex

1.7 The Efferent System

1.7.1 Effects of Olivocochlear Bundle Activity

1.7.2 Recording From Efferent Neurons

1.7.3 Protective Effects of Efferent Activity

1.7.4 Measuring Efferent Effects Using OAEs

1.7.5 Preventing Age-Related Synaptopathy?

1.8 Sound Localization

1.9 Summary

References

2 Brain Plasticity and Perceptual Learning

2.1 The External Environment

2.1.1 Critical and Sensitive Periods

2.2 Learning Paradigms

2.2.1 Nonassociative Learning

2.2.1.1 Habituation

2.2.1.2 Sensitization

2.2.2 Classical Conditioning

2.2.3 Instrumental or Operant Conditioning

2.2.4 Receptive Field and Tonotopic Map Plasticity in Auditory Cortex

2.2.5 Environmental Enrichment

2.3 Perceptual Learning

2.3.1 Bottom–Up Learning

2.3.2 Top–Down Learning

2.3.3 Extending the Reverse Hierarchy Theory

2.4 Auditory Training

2.4.1 Adults

2.4.2 Effects of Passive Exposure

2.4.3 Auditory Training in Cochlear Implant Patients

2.4.4 Auditory Learning in Children

2.5 AV Training

2.6 Music Training

2.7 Training by Playing Action Video Games

2.8 Summary

References

3 Multisensory Processing

3.1 Multimodal Auditory Cortical Areas

3.1.1 Animal Data

3.1.2 Human Findings

3.1.3 Hearing Loss Affects Multisensory Representation in Animals

3.1.4 Human Findings Following Sensory Deprivation

3.2 AV Interaction in Humans

3.2.1 The McGurk Effect

3.2.2 Lip Reading

3.2.3 Audio-visual Interaction in Development and Aging

3.2.3.1 Children

3.2.3.2 The Elderly

3.2.4 Role of Audio-visual Interaction in Cochlear Implant Use

3.3 Auditory–Somatosensory Interaction

3.3.1 The Dorsal Cochlear Nucleus

3.3.2 The Inferior Colliculus

3.3.3 The Auditory Thalamus and Cortex

3.4 Summary

References

II. The Problem

4 Hearing Problems

4.1 The Various Consequences of Noise Exposure

4.1.1 Structural Changes in the Auditory Periphery

4.1.2 Central Effects of Permanent Threshold Shifts

4.1.3 Central Effects of Temporary Threshold Shifts

4.1.4 Central Effects of Noise Exposure Without Threshold Shifts

4.2 Sound Localization Problems

4.2.1 Findings in Normal Hearing Humans

4.2.2 Hearing Loss and Sound Localization

4.2.3 Aging and Sound Localization

4.3 The Cocktail Party, Where Identification and Localization Come Together

4.4 Other Consequences of Hearing Loss

4.4.1 Hyperacusis

4.4.1.1 Peripheral Aspects

4.4.1.2 Central Mechanisms

4.4.2 Tinnitus

4.4.2.1 Tinnitus Pitch

4.4.2.2 Tinnitus Loudness

4.4.2.3 Tinnitus Masking and Residual Inhibition

4.4.2.4 The Role of Neural Synchrony in Tinnitus

4.4.2.5 Brain Areas Involved in Tinnitus

4.5 Neurological Disorders With Hearing Problems

4.5.1 Schizophrenia

4.5.2 Epilepsy

4.6 Hearing Disorders Without Hearing Sensitivity Loss

4.7 Nonauditory Effects of Hearing Loss

4.7.1 Balance Problems

4.7.2 Effects on Quality of Life

4.7.3 A Greater Risk for Dementia

4.7.4 Psychological Effects in Hearing-Impaired Children and Adolescents

4.8 Summary

References

5 Types of Hearing Loss

5.1 Site of Lesion Testing

5.1.1 Air/Bone Conduction Audiograms

5.1.2 Speech Discrimination Testing

5.1.3 Acoustic Immittance

5.1.3.1 Tympanometry

5.1.3.2 Middle Ear Muscle Reflex

5.1.4 Oto-Acoustic Emission Testing

5.1.5 Electrocochleography

5.1.6 Auditory Brainstem Response Testing

5.1.6.1 The Auditory Brainstem Response

5.1.6.2 The Stacked ABR

5.1.6.3 The Cochlear Hydrops Analysis Masking Procedure

5.1.7 The Auditory Steady-State Response

5.1.8 Tone Decay

5.2 Conductive Hearing Loss

5.2.1 Ossicular Interruption With Intact Tympanometry

5.2.2 Loss of Tympanometry, Malleus, and Incus

5.2.3 Otosclerosis

5.2.4 Collapse of the Tympanometry into the Middle Ear (Atelectasis)

5.2.5 Perforations of the Tympanometry

5.3 Use of Tympanometry in Detecting Conductive Hearing Loss

5.4 Sensorineural Hearing Loss

5.4.1 Noise-Induced Temporary Threshold Shifts

5.5 Loudness Recruitment

5.5.1 Compound Action Potentials and Recruitment

5.5.2 Single Auditory Nerve Fiber Responses and Recruitment

5.5.3 Central Nervous System and Recruitment

5.6 Auditory Neuropathy

5.6.1 Identification

5.6.2 Presynaptic Aspects of ANP

5.6.3 Postsynaptic Mechanisms of ANP

5.6.3.1 Dendritic Nerve Terminals

5.6.3.2 Axonal Neuropathies

5.6.3.3 Auditory Ganglion Cell Disorders

5.6.3.4 Myelin Disorders

5.6.3.5 Auditory Nerve Conduction Disorders

5.6.4 Electrocochleography Outcomes

5.6.5 Evoked Potentials Following Cochlear Implantation

5.6.6 Psychoacoustics

5.7 Vestibular Schwannoma

5.7.1 Detection Using ABR

5.7.2 Using the Stacked ABR

5.8 Ménière’s Disease

5.8.1 Phenomenology and Pathology

5.8.2 Natural History of Ménière’s Disease

5.8.3 Electrochleography

5.8.4 Diagnosis Using the Stacked ABR (CHAMP)

5.9 Age-Related Hearing Impairment (Presbycusis)

5.9.1 Changes in the Cochlea and Auditory Nerve

5.9.2 Changes in Auditory Cortex

5.10 Summary

References

III. The Causes

6 Causes of Acquired Hearing Loss

6.1 Occupational Noise Exposure in General

6.2 Recreational Noise and Music

6.2.1 Professional Musicians’ Exposure in Symphony Orchestras

6.2.2 Active Musicians’ Exposure at Pop/Rock Concerts

6.2.3 Passive Exposure at Concerts and Discos

6.2.4 Personal Listening Devices

6.3 Animal Research into Effects of Noise Exposure on the Brain

6.3.1 Necrosis and Apoptosis in Noise-Induced Hearing Loss

6.3.2 Delayed Effects of TTS Noise Exposure and Aging

6.3.3 Noise-Induced Permanent Hearing Loss in Animals

6.3.3.1 Subcortical Findings

6.3.3.2 Findings in Auditory Cortex and Thalamus

6.4 Ototoxicity

6.4.1 Salicylate

6.4.2 Platin Chemotherapy Drugs

6.4.3 Aminoglycosides

6.4.4 Mechanisms for Cisplatin and Aminoglycoside Ototoxicity

6.4.5 Diuretics

6.4.5.1 Furosemide

6.4.5.2 Ethacrynic Acid

6.4.6 Bacterial and Viral Infections

6.4.6.1 Bacterial Infections

6.4.6.2 Virus Infections

6.5 Long-Term Effects of Conductive Hearing Loss in Infancy

6.5.1 Effects in Humans

6.5.2 Animal Studies

6.6 Vestibular Schwannoma

6.7 Ménière’s Disease

6.8 Diabetes

6.8.1 Hearing Loss in Diabetes

6.8.2 Pathology

6.9 Summary

References

7 Epidemiology and Genetics of Hearing Loss and Tinnitus

7.1 Epidemiology of Sensorineural Hearing Loss

7.2 Epidemiology of Age-Related Hearing Loss

7.3 Epidemiology of Tinnitus

7.4 Epidemiology of Smoking and Alcohol Consumption

7.5 Epidemiology of Diabetes

7.6 Epidemiology of Otitis Media

7.7 Epidemiology of Auditory Neuropathy Spectrum Disorder

7.8 Genetics of Sensorineural Hearing Loss

7.8.1 Syndromic Hearing Loss

7.8.1.1 Usher Syndrome as an Example

7.8.2 Nonsyndromic Hearing Loss

7.8.2.1 GJB2 Mutations as an Example

7.9 Genetics of Otosclerosis

7.10 Genetics of Auditory Neuropathy

7.10.1 Otoferlin

7.10.2 The OPA1 gene

7.10.3 The AIFM1 gene

7.10.4 The PVJK gene

7.11 Gene Networks

7.12 Hereditary Versus Acquired Hearing Loss

7.12.1 Neonates

7.12.2 Infants and School Age

7.12.3 Genetic Susceptibility for Noise-Induced Hearing Loss

7.12.4 Genetic Susceptibility for Age-Related Hearing Impairment

7.13 Summary

References

8 Early Diagnosis and Prevention of Hearing Loss

8.1 Normal Human Auditory Development

8.2 Effects of Early Hearing Loss on Speech Production

8.3 Early Detection

8.3.1 Universal Newborn Hearing Screening: A Survey

8.3.2 Potential Problems with UNHS and Follow-Up Studies

8.4 Noise Exposure During Adolescence and Young Adulthood

8.5 Physical Hearing Protection

8.5.1 After Work Music

8.5.2 An Interlude About Earplugs

8.6 Education

8.6.1 Changing the Attitude About Noise Exposure

8.6.2 National Campaigns

8.7 Drug Protection Against Noise-Induced Hearing Loss

8.8 Summary

References

IV. The Treatments

9 Hearing Aids

9.1 Effects of Hearing Loss

9.1.1 Early Model Predictions on Speech Understanding

9.1.2 Age Effects on Aided Hearing in Noisy Environments

9.1.3 Effects of Hearing Aids on Sound Localization

9.1.4 Hearing Aids at the Cocktail Party

9.2 Acclimatization and Plasticity

9.3 Satisfaction and Quality of Life

9.4 Types of Hearing Aids

9.4.1 Behind-the-Ear Aids

9.4.2 In-the-Ear Aids

9.4.3 In-the-Canal Aids

9.4.4 Open-Fit Aids

9.4.5 Bone Conduction Hearing Aids

9.5 Processing

9.5.1 Digital Audio, Programmable Control

9.5.2 The Benefit of Bilateral Amplification

9.6 High-Frequency Hearing Loss, Loudness Recruitment, and Reduced SNR

9.6.1 High-Frequency Amplification

9.6.2 Frequency Compression

9.6.3 Amplitude Compression

9.6.4 Binaural Aids and Directional Microphones

9.6.5 Noise Reduction

9.6.6 Combatting Wind Noise

9.7 Hearing Aids and Music Perception

9.8 Hearing Aids and Tinnitus

9.9 Summary

References

10 Implantable Hearing Aids

10.1 Bone Conduction Mechanisms

10.2 Bone-Anchored Hearing Aids

10.2.1 General Performance

10.2.1.1 Single-Sided Deafness

10.2.1.2 Bilateral Hearing Loss

10.2.2 Application in Children

10.3 Implantable Active Middle Ear Devices

10.3.1 First Results

10.3.2 General Performance

10.3.2.1 The Vibrant Soundbridge

10.3.2.2 MET, Carina and Esteem

10.3.2.3 The Maxum Hearing Implant

10.3.3 Safety Issues

10.3.4 Middle Ear Implants Versus Conventional Hearing Aids

10.4 Summary

References

11 Cochlear Implants

11.1 Basics of Cochlear Implants

11.1.1 The Electrode Array

11.1.2 The Sound Processor

11.1.3 Spectral Sound Shape Representation

11.1.4 Coding of Single Frequencies and Complex Sounds

11.1.5 Amplitude Compression

11.1.6 Measurement of the Electrically Evoked Compound Action Potential

11.2 A Little History

11.3 Sound Processing Strategies

11.3.1 The Long Way to Speech Understanding With a Cochlear Implant

11.3.2 Description of Common Processor Strategies

11.3.2.1 Continuous Interleaved Sampling

11.3.2.2 SPEAK and ACE

11.3.2.3 HiRes 120: Current Steering

11.3.3 Newer Coding Strategies

11.3.3.1 Multichannel Envelope Modulation

11.3.3.2 MP3000

11.3.3.3 F0mod

11.3.3.4 Enhanced Envelope Encoded Tone (eTone)

11.3.4 Mimicking Spontaneous Activity in the Auditory Nerve

11.4 Temporal Processing With a Cochlear Implant

11.4.1 Refractoriness of Auditory Nerve Activity to Cochlear Implant Stimulation

11.4.2 Adaptation to CI Stimulation

11.4.3 Amplitude Modulation Detection

11.4.4 Spectral-Ripple Detection

11.5 Effects of Age on Implantation

11.5.1 Effects of Early Cochlear Implantation: Electrophysiological Measures

11.5.2 Auditory Deprivation Effects on Auditory Cortex

11.5.3 Effects of Early Implantation on Speech and Language

11.5.4 Cochlear Implantation in the Elderly

11.6 Cochlear Implants and Music Perception

11.7 One-Sided or Bilateral Implantation?

11.8 Cochlear Implantation and Tinnitus

11.8.1 Tinnitus in the CI Population

11.8.2 Tinnitus in Single-Sided Deafness

11.9 Modeling Studies

11.10 Summary

References

V. The Future

12 Auditory Brainstem and Midbrain Implants

12.1 Auditory Brainstem Implants

12.1.1 Surface Electrodes

12.1.2 A Note on Electrode Placement

12.1.3 Penetrating Electrodes

12.1.4 Performance With Auditory Brainstem Implants

12.2 Auditory Midbrain Implants

12.2.1 First Results

12.2.2 Toward a Better Auditory Midbrain Implant Design

12.3 Summary

References

13 Repairing and Building New Ears

13.1 Gene Therapy for Hereditary Hearing Loss

13.2 Regenerating Hair Cells

13.3 Birds Can Do It

13.3.1 Structural Recovery After Noise Trauma in Birds

13.3.2 Functional Recovery After Noise Trauma in Birds

13.4 Trials in Mammals

13.4.1 The Problem

13.4.2 Transplantation of Inner Ear Stem Cells

13.4.3 Cell Cycle Reentry

13.4.4 Transdifferentiation of Supporting Cells into Hair Cells

13.5 Outlook

References

Appendix A: Electrocochleography From the Promontory and via a Cochlear Implant

A.1 Introduction

A.2 Methods

A.2.1 Stimuli

A.2.2 Recording Sites

A.3 Receptor Potentials

A.3.1 Cochlear Microphonics

A.3.2 Summating Potentials

A.4 The Compound Action Potential

A.5 Comparing the CAP and the eCAP

A.5.1 The Composition of the CAP Recorded From the Promontory

A.5.2 The eCAPs as Recorded by Cochlear Implants

References

Index

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