Systematic Groupings in Hearing Impaired Consonant Perception

Auditory training programs are currently being explored as a method of improving hearing impaired (HI) speech perception; precise knowledge of a patient’s individual differences in speech perception allows one to more accurately diagnose how a training program should be implemented. Remapping or variations in the weighting of acoustic cues, due to auditory plasticity, can be examined with the detailed confusion analyses that we have developed at UIUC. We show an analysis of the responses of 17 ears with sensorineural hearing loss to consonant-vowel stimuli, composed of 14 English consonants followed by the vowel /A/, presented in quiet and speechshaped noise. Although the tested tokens are noise-robust and unambiguous for normal-hearing listeners, the subtle natural variations in signal properties can lead to systematic differences for HI listeners. Specifically, our recent findings have shown token-dependent individual variability in error and confusion groups for HI listeners. A clustering analysis of the confusion data shows that HI listeners fall into specific groups. Many of the token-dependent confusions that define these groups can also be observed for normal-hearing listeners, under higher noise levels or filtering conditions. These HI-listener groups correspond to different acoustic-cue weighting schemes, highlighting where auditory training should be most effective.