Temporal analysis and stimulus fluctuation in listeners with normal and impaired hearing.

The first experiment investigated the effects of mild to moderate sensorineural hearing impairment on temporal analysis for noise stimuli of varying bandwidth. Tasks of temporal gap detection, amplitude modulation (AM) detection, and AM discrimination were examined. Relatively high levels of stimulation were used in order to reduce the possibility that the results of the listeners with hearing impairment would be influenced strongly by audibility. A general summary of results was that there was relatively great interlistener variation among the listeners with hearing impairment, with most listeners showing normal performance and some showing degraded performance, regardless of the bandwidth of the stimulus carrying the temporal information. A second experiment investigated the hypothesis that listeners with sensorineural hearing impairment might have poor gap detection due to loudness recruitment. Here, gap markers were presented at levels where loudness growth was steeper for the listeners with hearing impairment than for the listeners with normal hearing. Although gap detection was sometimes poorer in listeners with hearing impairment than in listeners with normal hearing, there was no clear relation between gap detection performance and loudness recruitment in listeners with mild to moderate sensorineural hearing impairment.