Comparing the influence of auditory streaming cues on binaural pitch fusion in normal-hearing and hearing-impaired listeners

Abstract

Binaural pitch fusion occurs when dichotic signals eliciting a different pitch are perceived as one sound. Previously, we investigated the effects of auditory streaming cues on binaural fusion using a modification of the ABA streaming paradigm. A dichotic stimulus (fixed tone at frequency fref in the reference ear and variable frequency in the contralateral ear) was presented at alternating intervals with up to 3 “capture” tones at fref. Participants reported whether they perceived galloping or two streams. Binaural fusion frequency range decreased with the number of capture tones and longer inter-stimulus intervals (ISIs), suggesting competition of sequential grouping with capture tones versus simultaneous grouping (fusion) with the dichotic tone. In the present study, we compared the effects in NH and hearing-impaired (HI) listeners. Preliminary data from 13 NH and 5 HI listeners suggest greater reductions in fusion range with number of capture tones and with longer ISI in HI listeners, especially in listeners with broad binaural fusion. These findings indicate that auditory grouping cues can reduce binaural fusion in both NH and HI listeners. Funded by NIH/NIDCD R01DC013307.