title: Forward-masking recovery and the assumptions of the temporal masking curve method of inferring cochlear compression.
abstract: The temporal masking curve (TMC) method is a behavioral technique for inferring human cochlear compression. The method relies on the assumptions that in the absence of compression, forward-masking recovery is independent of masker level and probe frequency. The present study aimed at testing the validity of these assumptions. Masking recovery was investigated for eight listeners with sensorineural hearing loss carefully selected to have absent or nearly absent distortion product otoacoustic emissions. It is assumed that for these listeners basilar membrane responses are linear, hence that masking recovery is independent of basilar membrane compression. TMCs for probe frequencies of 0.5, 1, 2, 4, and 6 kHz were available for these listeners from a previous study. The dataset included TMCs for masker frequencies equal to the probe frequencies plus reference TMCs measured using a high-frequency probe and a low, off-frequency masker. All of the TMCs were fitted using linear regression, and the resulting slope and intercept values were taken as indicative of masking recovery and masker level, respectively. Results for on-frequency TMCs suggest that forward-masking recovery is generally independent of probe frequency and of masker level and hence that it would be reasonable to use a reference TMC for a high-frequency probe to infer cochlear compression at lower frequencies. Results further show, however, that reference TMCs were sometimes shallower than corresponding on-frequency TMCs for identical probe frequencies, hence that compression could be overestimated in these cases. We discuss possible reasons for this result and the conditions when it might occur.
authors.affiliation: Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain Grupo de Audiología, Instituto de Investigación Biomédica de Salamanca, Salamanca, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Pérez-González
authors.affiliation: Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain Grupo de Audiología, Instituto de Investigación Biomédica de Salamanca, Salamanca, Spain.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Johannesen
authors.affiliation: Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain Grupo de Audiología, Instituto de Investigación Biomédica de Salamanca, Salamanca, Spain Departamento de Cirugía, Facultad de Medicina, Universidad de Salamanca, Salamanca, Spain ealopezpoveda@usal.es.
authors.forename: Enrique A
authors.initials: EA
authors.lastname: Lopez-Poveda
mesh_terms: D000161:Acoustic Stimulation; D000368:Aged; D000369:Aged, 80 and over; D001301:Audiometry, Pure-Tone; D001307:Auditory Perception; D001309:Auditory Threshold; D003051:Cochlea / Q000503:physiopathology*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017084:Otoacoustic Emissions, Spontaneous; D010470:Perceptual Masking; D013997:Time Factors
keywords: DPOAEs; cochlear nonlinearity; middle-ear muscle reflex; otoacoustic emissions