Clinical Audiology: An Introduction

817 Pages·2008·14.37 MB·English

by  Brad A. Stach

Clinical
Audiology
An Introduction
SECOND EDITION
For my daughters,
Madeline Elizabeth and Rachael Hanoven Stach
Clinical
Audiology
An Introduction
SECOND EDITION
Brad A. Stach, Ph.D.
Division of Audiology
Department of Otolaryngology—Head & Neck Surgery
Henry Ford Hospital
Detroit, Michigan
Australia • Brazil • Japan • Korea • Mexico • Singapore • Spain • United Kingdom • United States
Clinical Audiology: An Introduction, © 2010 Delmar, Cengage Learning
Second edition
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Brad A. Stach, Ph.D.
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Contents
Preface / xix
About the Author / xxiii
Acknowledgments / xxv
1
THE PROFESSION OF AUDIOLOGY IN
THE UNITED STATES
Learning Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
What Is an Audiologist? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
What Is an Audiologist’s Role? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Identif cation / 5
Assessment and Diagnosis / 5
Treatment / 5
Education / 7
Prevention / 7
Research / 8
Related Activities / 8
Scope of Practice / 8
Where Do Audiologists Practice? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Private Practice / 11
Physician’s Practices / 13
Hospitals and Medical Centers / 14
Hearing and Speech Clinics / 15
Schools / 15
Universities / 16
Hearing Instrument Manufacturers / 17
Industry / 18
v
vi CONTENTS
Relation to Other Professions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Otolaryngology / 19
Other Medical Specialties / 21
Speech-Language Pathology / 22
Nonaudiologist Hearing Aid Dispensers / 24
Other Professionals / 24
The Evolution of Audiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
The Professional Heritage of Audiology / 25
From Academic Discipline to Health-care Profession / 25
From Communication Disorders to the Hearing Profession / 26
From Teacher-Training Model of Education to Health-Care Model / 27
From Certif cation to Licensure Model / 27
The Clinical Heritage of Audiology / 28
Audiology’s Beginnings (Before 1950) / 29
Audiology as an Academic Discipline (1950s and 1960s) / 30
Audiology as a Clinical Profession (1970s and Beyond) / 31
Professional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Becoming an Audiologist / 33
Academic and Clinical Requirements / 34
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Short Answer Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Discussion Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Information Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Organizations / 38
Resources / 39
2
THE NATURE OF HEARING
Learning Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
The Nature of Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
What Is Sound? / 42
Properties of Sound / 45
Intensity / 46
Frequency / 51
Phase / 51
Spectrum / 52
The Auditory System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Outer Ear / 56
Middle Ear / 59
Anatomy / 59
Physiology / 60
CONTENTS vii
Inner Ear / 61
Anatomy / 62
Physiology / 66
Auditory Nervous System / 71
The VIIIth Cranial Nerve / 71
The Central Auditory Nervous System / 72
The Vestibular System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Anatomy / 77
Physiology / 79
How We Hear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Absolute Sensitivity of Hearing / 81
The Nature of Hearing Sensitivity / 82
The Audiogram / 84
Differential Sensitivity / 89
Properties of Pitch and Loudness / 92
Measurement of Sound / 93
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Short Answer Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Discussion Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
3
THE NATURE OF HEARING LOSS
Learning Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Types of Hearing Disorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Hearing Sensitivity Loss / 102
Conductive Hearing Loss / 103
Sensorineural Hearing Loss / 105
Mixed Hearing Loss / 109
Suprathreshold Hearing Disorder / 110
Retrocochlear Hearing Disorder / 111
Auditory Processing Disorder / 113
Functional Hearing Loss / 116
Impact of Hearing Disorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Patient Factors / 118
Degree and Conf guration of Hearing Sensitivity Loss / 119
Type of Hearing Loss / 126
Conductive Hearing Loss / 126
Sensorineural Hearing Loss / 127
Retrocochlear Hearing Loss / 128
Auditory Processing Disorder / 129
viii CONTENTS
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Short Answer Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Discussion Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
4
CAUSES OF HEARING DISORDER
Learning Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Auditory Pathology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Conductive Hearing Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Congenital Outer- and Middle-Ear Anomalies / 138
Impacted Cerumen / 141
Other Outer-Ear Disorders / 143
Otitis Media with Effusion / 143
Complications of OME / 147
Tympanic-Membrane Perforation / 147
Cholesteatoma / 149
Tympanosclerosis / 150
Otosclerosis / 150
Other Middle-Ear Disorders / 151
Sensory Hearing Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Congenital and Inherited Sensory Hearing Disorders / 153
Inner-Ear Anomalies / 153
Teratogenic Factors / 155
Syndromic Hereditary Hearing Disorder / 156
Nonsyndromic Hereditary Hearing Disorder / 158
Acquired Sensory Hearing Disorders / 159
Perinatal Factors / 159
Noise-Induced Hearing Loss / 160
Trauma / 164
Infections / 165
Ototoxicity / 167
Ménière’s Disease / 170
Presbyacusis / 171
Autoimmune Inner-Ear Disease / 175
Cochlear Otosclerosis / 176
Idiopathic Sudden Sensorineural Hearing Loss / 177
Neural Hearing Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Auditory Neuropathy / 178
VIIIth Nerve Tumors and Disorders / 179
Brainstem Disorders / 181
CONTENTS ix
Temporal-Lobe Disorder / 182
Other Nervous System Disorders / 182
Vestibular Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Benign Paroxysmal Positional Vertigo / 184
Superior Canal Dehiscence / 185
Vestibulotoxicity / 185
Vestibular Neuritis / 186
Ménière’s Disease / 186
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Short Answer Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Discussion Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Articles and Books / 194
Web Sites / 195
5
INTRODUCTION TO HEARING ASSESSMENT
Learning Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
The First Question . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Referral-Source Perspective / 199
Importance of the Case History / 201
The Audiologist’s Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
Evaluating Outer- and Middle-Ear Function / 208
Estimating Hearing Sensitivity / 212
Determining Type of Hearing Loss / 214
Measuring Speech Recognition / 217
Measuring Auditory Processing / 218
Measuring the Impact of Hearing Loss / 219
Screening Hearing Function / 221
Newborn Hearing Screening / 224
School-Age Screening / 227
Workplace Screening / 228
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Short Answer Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Discussion Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Articles and Books / 232
Web Sites / 234