Abstract |
Threshold and amplitude measurements were made for fixed frequency Bekesy pure tones on subjects with normal hearing, sensorineural hearing impairment, and functional hearing loss. Following conventional Bekesy audiometry (intensity change 4 dB/sec), -20 dB was added to a signal at the threshold of audibility (bottom of the spike). When sensation was lost at the threshold of inaudibility (top of the spike), +20 dB was added. Adding +/- 20 dB in subjects with normal hearing reduced the amplitude of the spike about 4 dB, corresponding to 1 second, for both pulsed and continuous tones. Adding +/- 40 dB produced essentially similar findings. Adding +/- 20 dB in subjects with sensorineural loss with reduced amplitude of continuous tone tracings also reduced the amplitude approximately 4 dB for pulsed tones, but 3 dB, corresponding to 0.75 seconds, for continuous tones. Abnormal rapid adaptation may account for this reduced amplitude of the spikes. A subject with multiple sclerosis producing excessive abnormal adaptation showed spectacular increased amplitude for continuous tone only when -20 dB was added at bottoms and +20 dB at tops of spikes. An explanation based on slow adaptation is offered. Subjects with functional hearing loss may emphasize either time or intensity in their inappropriate responses when +/- 20 dB is added at tops and/or bottoms of spikes.
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Authors | I M Young, F Harbert |
Journal | Yonsei medical journal
(Yonsei Med J)
Vol. 31
Issue 3
Pg. 197-204
(Sep 1990)
ISSN: 0513-5796 [Print] Korea (South) |
PMID | 2281679
(Publication Type: Comparative Study, Journal Article)
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Topics |
- Audiometry, Pure-Tone
- Auditory Threshold
- Hearing Loss, Functional
(physiopathology)
- Hearing Loss, Sensorineural
(physiopathology)
- Humans
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