Estimating peripheral gain and compression using fixed-duration masking curves

Abstract

Estimates of human basilar membrane gain and compression obtained using temporal masking curve (TMC) and additivity of forward masking (AFM) methods with long-duration maskers or long masker-signal silent intervals may be affected by olivocochlear efferent activation, which reduces basilar membrane gain. The present study introduces a fixed-duration masking curve (FDMC) method, which involves a comparison of off- and on-frequency forward masker levels at threshold as a function of masker and signal duration, with the total masker-signal duration fixed at 25 ms to minimize efferent effects. Gain and compression estimates from the FDMC technique were compared with those from TMC (104-ms maskers) and AFM (10- and 200-ms maskers) methods. Compression estimates over an input-masker range of 40-60 dB sound pressure level were similar for the four methods. Maximum compression occurred at a lower input level for the FDMC compared to the TMC method. Estimates of gain were similar for TMC and FDMC methods. The FDMC method may provide a more reliable estimate of BM gain and compression in the absence of efferent activation and could be a useful method for estimating effects of efferent activity when used with a precursor sound (to trigger efferent activation), presented prior to the combined masker-signal stimulus.

Accounting for nonmonotonic precursor duration effects with gain reduction in the temporal window model

“…In contrast, other studies support the assumption that the 2.4-kHz stimuli used in this study are represented linearly at a 4-kHz CF (Jennings and Strickland, 2012b;Yasin et al, 2013). The primary difference between these studies is the masking method used.…”

“…The basilar membrane response to the 2.4-kHz masker was assumed to be approximately linear at the place with a CF corresponding to the 4-kHz signal frequency. This assumption is supported by previous psychophysical studies with short maskers (Jennings and Strickland, 2012b;Yasin et al, 2013). It was also assumed that the masker produced little-to-no gain reduction for the signal because the total duration of the 20-ms masker and the 6-ms signal fell approximately within the 25-ms MOCR onset delay and the MOCR effect builds gradually.…”

Effect of auditory efferent time-constant duration on speech recognition in noise

“…Future work to evaluate the effect of efferent activation on speech recognition in noise could look into the relative contributions of different types neural fibers (lowand high-spontaneous rate) and their respective roles in the linearization of the compression applied to the signal response during efferent activation (Yasin et al, 2013(Yasin et al, , 2014.…”

Physiology, Psychoacoustics and Cognition in Normal and Impaired Hearing

“…Psychoacoustical studies suggest the efferent effect appears to decrease as the precursor frequency is set higher or lower in frequency than the subsequently presented masker (Bacon and Viemeister 1985;Bacon and Moore 1986). The present study uses a psychoacoustical forward-masking technique [fixed-duration masking curve (FDMC) method (Yasin et al 2013a(Yasin et al , b, 2014] in which a precursor sound is presented to elicit the efferent response. The FDMC method avoids the confounds of previous forward-masking methods used to measure the efferent effect by using a combined duration of the masker-plus-signal stimulus of 25 ms, which is within the efferent onset delay.…”