For listeners with cochlear hearing loss, cochlear damage may include "dead regions" with no functioning inner hair cells and/or associated neurons. Recent studies indicate that amplifying frequencies more than 1.7 times the edge frequency (1.7Fe) of a high-frequency dead region is unlikely to improve (and may reduce) speech scores [Vickers et al., J. Acoust. Soc. Am. 110, 1164–1175 (2001); Baer et al., J. Acoust. Soc. Am. 112, 1133–1144 (2002)]. These results were taken as evidence that tests to identify dead regions could improve hearing aid fitting. In the current study, practicing audiologists examined audiograms of listeners diagnosed as having high-frequency dead regions. The audiologists were given no specific information regarding dead regions for any individual, and were asked to base amplification decisions entirely on the audiograms. Most audiologists did not recommend amplification of frequencies with hearing losses exceeding 90 dB HL. Reexamination of speech results reported by Vickers et al. and Baer et al. indicated that limiting amplification based on audiograms alone (90-dB rule) or on specific testing for dead regions (1.7Fe rule) produced similar performance. Thus, testing for dead regions may not provide important information for hearing aid fitting that is not already available in the audiogram.
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