Factors affecting psychophysical tuning curves for hearing-impaired subjects with high-frequency dead regions.

摘要: A dead region (DR) is a of the cochlea where there are no functioning inner hair cells and/or neurons. DRs can be detected using threshold-equalizing-noise (TEN) test, but psychophysical tuning curves (PTCs) sometimes used to give more precise estimate edge frequency DR; shifted tip PTC indicates DR. We show here that shapes PTCs for hearing-impaired subjects influenced by detection beats and simple difference tones (SDTs). As result, have tips at f(s), even when f(s) falls in were measured with mild moderate low-frequency severe high-frequency hearing loss sinusoidal narrowband noise maskers (80-, 160-, 320-Hz wide): (1) quiet; (2) presence additional lowpass filtered (LF noise) designed mask SDTs; (3) pair interfere (MDI tones). In condition (1), often W-shaped, sharp f(s). This occurred less wider bandwidths. For good hearing, LF reduced or eliminated suggesting this was partly caused SDTs. 80-Hz wide maskers, addition MDI masker level required threshold frequencies adjacent nearly all subjects, strong influence beat detection. To minimize beats, we recommend bandwidth 160 (preferably) 320 Hz. cases near-normal low frequencies, an