| Preface |
|
xi | |
|
1 Common Clinical Encounters: Do We Really Know Them? |
|
|
1 | (34) |
|
|
|
1 | (1) |
|
The Outer Ear and Ear Canal: What Do These Offer for the Understanding of Speech? |
|
|
2 | (3) |
|
The Occlusion Effect: What Exactly Is It? |
|
|
5 | (3) |
|
The Middle Ear: Why Do We Have Middle Ears in the First Place? |
|
|
8 | (3) |
|
The Middle Ear Adds Some 30 to 35 dB: Why Can a Conductive Hearing Loss Be More Than This? |
|
|
11 | (2) |
|
Why Are Hearing Thresholds in dB Sound Pressure Level (SPL) Shaped as a Curve? |
|
|
13 | (3) |
|
Why Does Carhart's Notch Appear With Otosclerosis? |
|
|
16 | (2) |
|
Acoustic Reflexes: Why Do We Really Have Them Anyway? |
|
|
18 | (2) |
|
Noise-Induced Hearing Loss: Why Does It Have Its Shape? |
|
|
20 | (3) |
|
Meniere's Disease: Why Does It Often Initially Present With a Rising Audiogram? |
|
|
23 | (3) |
|
A Word About Presbycusis: Why Does It Mainly Affect the High Frequencies? |
|
|
26 | (3) |
|
Speech Discrimination: Why Is It Different From Client to Client? |
|
|
29 | (1) |
|
Postscript: The Complementary Roles of AR Testing and OAE Testing |
|
|
30 | (2) |
|
|
|
32 | (3) |
|
2 The Cochlea and Outer Hair Cell Damage |
|
|
35 | (26) |
|
|
|
35 | (3) |
|
A Sketch of Cochlear Anatomy and Physiology |
|
|
38 | (6) |
|
Inner and Outer Hair Cells: Structure and Function |
|
|
44 | (2) |
|
The Passive, Asymmetric Traveling Wave |
|
|
46 | (3) |
|
OHCs and Active Traveling Wave |
|
|
49 | (2) |
|
Outer Hair Cells and Oto-Acoustic Emissions |
|
|
51 | (1) |
|
Hearing Aids for Sensory SNHL Caused by OHC Damage |
|
|
52 | (6) |
|
|
|
58 | (3) |
|
3 Inner Hair Cell Damage, Traveling Wave Envelopes, and Cochlear Dead Regions |
|
|
61 | (28) |
|
|
|
61 | (1) |
|
IHCs: Functions and Consequences of Damage |
|
|
62 | (2) |
|
Asymmetry of the Traveling Wave Envelope |
|
|
64 | (2) |
|
VIII Nerve Tuning Curves: Also Asymmetric |
|
|
66 | (3) |
|
Psychophysical Tuning Curves: Also Asymmetric |
|
|
69 | (3) |
|
Traveling Wave Asymmetry and Audiograms Associated With Cochlear Dead Regions |
|
|
72 | (6) |
|
Low-Frequency Dead Regions and the Moderate Reverse Audiogram |
|
|
72 | (2) |
|
High-Frequency Dead Regions and the Severe, Precipitous Audiogram |
|
|
74 | (3) |
|
Other Audiograms Associated With Cochlear Dead Regions |
|
|
77 | (1) |
|
Moore's Threshold Equalizing Noise (TEN) Test for Cochlear Dead Regions |
|
|
78 | (2) |
|
|
|
80 | (3) |
|
Perceptions of Sounds Within a Dead Hair Cell Region |
|
|
83 | (2) |
|
Dead Regions and Implications for Amplification |
|
|
85 | (1) |
|
|
|
86 | (1) |
|
|
|
87 | (2) |
|
4 Early Hearing Aid Fitting Methods: Why So Many? |
|
|
89 | (36) |
|
|
|
89 | (3) |
|
Lenses for the Eye Versus Hearing Aids for the Ear |
|
|
92 | (3) |
|
SNHL: The Audibility Problem and the Speech-in-Noise Problem |
|
|
95 | (5) |
|
A Short History of Hearing Aid Technology |
|
|
100 | (4) |
|
|
|
104 | (3) |
|
Dynamic Range: Reduced Versus Normal |
|
|
107 | (3) |
|
A Short History of Linear-Based Fitting Methods |
|
|
110 | (12) |
|
|
|
122 | (3) |
|
5 Verification with Real Ear Measures: Yesterday and Today |
|
|
125 | (38) |
|
|
|
125 | (3) |
|
Real Ear Measurement: Components |
|
|
128 | (4) |
|
Yesterday's Real Ear Measurement: Procedures |
|
|
132 | (7) |
|
Gain in dB Versus Output in dB SPL |
|
|
139 | (3) |
|
Effects of Compression on Gain (dB) Versus Output (dB SPL) |
|
|
142 | (4) |
|
Today's Real Ear Measurement |
|
|
146 | (3) |
|
Those Awful Transforms! From the Audiogram to the SPL-o-Gram |
|
|
149 | (5) |
|
Procedures in Today's Real Ear Measurement |
|
|
154 | (3) |
|
|
|
157 | (3) |
|
|
|
160 | (1) |
|
|
|
161 | (2) |
|
6 Compression and the DSL and NAL Fitting Methods |
|
|
163 | (38) |
|
|
|
163 | (2) |
|
Two Types of Compression for Two Types of SNHL |
|
|
165 | (1) |
|
Loudness Growth and Consequences of Reduced Dynamic Range |
|
|
166 | (6) |
|
|
|
172 | (9) |
|
|
|
173 | (4) |
|
DSL4 and Acoustic Transforms |
|
|
177 | (3) |
|
|
|
180 | (1) |
|
The NAL-NL1 Fitting Method |
|
|
181 | (6) |
|
NAL-NL1 and Loudness Equalization of Adjacent Speech Frequencies |
|
|
182 | (3) |
|
|
|
185 | (2) |
|
Target Comparisons Among DSL4, DSL5, NAL-NL1, and NAL-NL2 |
|
|
187 | (7) |
|
Target Comparisons for DSL4 and NAL-NL1 |
|
|
187 | (5) |
|
Target Comparisons for DSL5 Child, DSL5 Adult, and NAL-NL1 |
|
|
192 | (1) |
|
Target Comparisons for NAL-NL1 and NAL-NL2 |
|
|
192 | (1) |
|
Target Comparisons for DSL5 Adult Version and NAL-NL2 |
|
|
193 | (1) |
|
Fitting Methods: Islands in the Setting Sun? |
|
|
194 | (3) |
|
|
|
197 | (1) |
|
|
|
198 | (3) |
|
7 Compression in Analog Hearing Aids: Historical Development |
|
|
201 | (60) |
|
|
|
201 | (2) |
|
The 1990s: The Golden Age of Compression |
|
|
203 | (2) |
|
A Word About Input/Output Functions |
|
|
205 | (3) |
|
Input Compression Versus Output Compression |
|
|
208 | (6) |
|
Output Compression on an I/O Function |
|
|
211 | (1) |
|
Input Compression on an I/O Function |
|
|
212 | (2) |
|
Output Limiting Compression Versus Wide Dynamic Range Compression |
|
|
214 | (14) |
|
Output Limiting Compression (OLC) |
|
|
214 | (4) |
|
Adjustment of MPO in OLC Hearing Aids |
|
|
218 | (1) |
|
Wide Dynamic Range Compression (WDRC) |
|
|
219 | (4) |
|
Adjustment of Gain in WDRC: The "TK" Control |
|
|
223 | (2) |
|
Clinical Applications of Output Limiting Compression and WDRC |
|
|
225 | (3) |
|
BILL and TILL: Two Types of Early WDRC |
|
|
228 | (4) |
|
Programmable and Multichannel Hearing Aids |
|
|
232 | (9) |
|
Programmable Hearing Aids |
|
|
233 | (2) |
|
Multichannel Hearing Aids |
|
|
235 | (6) |
|
Common Clinical Combinations of Compression |
|
|
241 | (5) |
|
A Compression Combination for Mild-to-Moderate SNHL |
|
|
243 | (2) |
|
A Compression Combination for Severe Hearing Loss |
|
|
245 | (1) |
|
Dynamic Aspects of Compression |
|
|
246 | (9) |
|
|
|
249 | (1) |
|
|
|
250 | (1) |
|
|
|
250 | (2) |
|
|
|
252 | (1) |
|
|
|
252 | (3) |
|
Interaction Between Static and Dynamic Aspects of Compression |
|
|
255 | (1) |
|
|
|
256 | (2) |
|
|
|
258 | (1) |
|
Recommended Readings From a Long Time Ago |
|
|
259 | (1) |
|
|
|
259 | (2) |
|
8 Compression and Other Features in Digital Hearing Aids |
|
|
261 | (52) |
|
|
|
261 | (2) |
|
"Digital" Versus "Analog" |
|
|
263 | (4) |
|
In Situ Audiometric Testing |
|
|
267 | (1) |
|
|
|
268 | (6) |
|
Automatic Feedback Reduction |
|
|
274 | (4) |
|
Digital Combinations of Compression |
|
|
278 | (7) |
|
|
|
285 | (5) |
|
Types of Digital Noise Reduction (DNR) |
|
|
290 | (15) |
|
Noise Reduction with Amplitude Modulation |
|
|
294 | (4) |
|
Statistical Distribution of Speech Versus Noise Intensity |
|
|
298 | (3) |
|
|
|
301 | (1) |
|
Two Examples of Early Digital Hearing Aids |
|
|
302 | (3) |
|
Digital Hearing Aids: State of the Art and the Future |
|
|
305 | (4) |
|
|
|
309 | (2) |
|
|
|
311 | (2) |
|
9 Clinical Benefits of Directional Microphones Versus Digital Noise Reduction |
|
|
313 | (32) |
|
|
|
313 | (2) |
|
|
|
315 | (16) |
|
How Directional Microphones Work |
|
|
318 | (4) |
|
Directional Microphones: How They Are Measured |
|
|
322 | (6) |
|
Directional Microphones and Further Features |
|
|
328 | (3) |
|
Digital Noise Reduction (DNR) Revisited |
|
|
331 | (7) |
|
Is Optimal Speech Intelligibility Really the Goal? |
|
|
338 | (2) |
|
|
|
340 | (1) |
|
|
|
341 | (4) |
|
10 Adaptive Dynamic Range Optimization: An Alternative to WDRC |
|
|
345 | (20) |
|
|
|
345 | (2) |
|
The Speech Waveform: ADRO Versus WDRC |
|
|
347 | (4) |
|
Optimizing the Dynamic Range of Input Speech |
|
|
351 | (1) |
|
ADRO's Subjective In Situ Fitting Method |
|
|
352 | (2) |
|
|
|
354 | (1) |
|
Application of ADRO's Comfort and Audibility Rules |
|
|
355 | (2) |
|
|
|
357 | (3) |
|
ADRO: A Return to Simplicity? |
|
|
360 | (4) |
|
|
|
364 | (1) |
| Appendix A Classes of Hearing Aid Amplifiers, A, B, D, and H: Where's Class C? |
|
365 | (4) |
Appendix B Answers to Review Questions of
Chapter 7 |
|
369 | (2) |
| Index |
|
371 | |
