Predictive factors for broad binaural pitch fusion in adults with hearing aids and cochlear implants

Abstract

Many adults with hearing loss who use hearing aids (HAs) and/or cochlear implants (CIs) have broad binaural pitch fusion, such that sounds with large pitch differences are fused across ears, leading to difficulties separating voices in multi-talker environments. However, there is individual variation. The goal of the current study was to investigate whether auditory experience factors explain this variation in broad binaural fusion. Binaural fusion was measured in adults with various hearing device combinations: 26 bilateral HA, 25 bimodal CI, and 27 bilateral CI users. Fusion ranges were measured by simultaneous, dichotic presentation of reference and comparison stimuli in opposite ears, and varying the comparison stimulus to find the range that fused with the reference stimulus. Factors examined included age at testing, degree of HL, amount of amplification, age of onset of HL, duration of HL without CI, and duration of HA, bimodal CI, and bilateral CI use. Preliminary analyses suggest that broad fusion is correlated with long durations of HA use; further analyses using multivariable models will be described. The findings will indicate how hearing device experience may influence binaural pitch fusion. [Work supported by NIH grant R01 DC013307.]