An examination of gender differences in DPOAE phase delay measurements in normal-hearing human adults

Autor: David Brown, Barry P. Kimberley, D.M Bowman
Rok vydání: 2000
Předmět:
Zdroj: Hearing research. 142(1-2)
ISSN: 0378-5955
Popis: This study examined gender differences in f 1 - and f 2 -sweep distortion product otoacoustic emission (DPOAE) phase delay measures in 60 normal-hearing human adults. Phase delay measures were obtained at six different f 2 frequencies ranging from 1.1 to 6.0 kHz ( f 2 / f 1 ratios were 1.1–1.3). Primary levels for f 2 were 45 and 50 dB SPL ( f 1 was 15 dB> f 2 ). Gender differences have been observed in normal-hearing human adults in both auditory brainstem response (ABR) and f 1 -sweep DPOAE studies. Gender differences in delay have been attributed to differences in the average length of the cochlea, where female cochleas are 13% shorter than male cochleas. Previously, the authors have proposed that the f 1 -sweep phase delay estimate is predominantly composed of a level-independent transport time to the site of DPOAE generation and a small proportion of the level and frequency-dependent filter build-up time. The f 2 -sweep delay also contains the transport time, however, it is predominantly composed of the filter build-up time. Therefore, delay differences between stimulation paradigms are equal to a proportion of the filter build-up time. In this study, mean f 1 - and f 2 -sweep delays were significantly longer in male ears than female ears at 1.1 kHz (45 and 50 dB). At 50 dB, f 1 -sweep phase delay measures were 18% longer in male ears (6.5 ms) than female ears (5.5 ms). Mean f 2 -sweep delays were 23% longer in male ears (10.0 ms) than female ears (8.1 ms). This gender difference was not observed when the isolated filter build-up time was calculated from the DPOAE phase delay difference. These observations may therefore be attributed to a gender-related anatomical difference in cochlear length.
Databáze: OpenAIRE
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