title: 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.
authors.affiliation: Ear Institute, University College London, 332 Grays Inn Road, London WC1X 8EE, United Kingdom. i.yasin@ucl.ac.uk
authors.forename: Ifat
authors.initials: I
authors.lastname: Yasin
authors.forename: Vit
authors.initials: V
authors.lastname: Drga
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Plack
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology; D001489:Basilar Membrane / Q000502:physiology*; D003056:Cochlear Nerve / Q000502:physiology*; D004525:Efferent Pathways / Q000502:physiology*; D005260:Female; D006801:Humans; D008144:Loudness Perception / Q000502:physiology; D008297:Male; D009847:Olivary Nucleus / Q000502:physiology*; D010470:Perceptual Masking / Q000502:physiology*; D010898:Pitch Perception / Q000502:physiology; D011571:Psychoacoustics; D012016:Reference Values; D013018:Sound Spectrography; D055815:Young Adult