High-Frequency Sensorineural Hearing Loss Alters Cue-WeightingStrategies for Discriminating Stop Consonants in Noise

摘要

There is increasing evidence that hearing-impaired (HI) individuals do not usethe same listening strategies as normal-hearing (NH) individuals, even whenwearing optimally fitted hearing aids. In this perspective, bettercharacterization of individual perceptual strategies is an important step towarddesigning more effective speech-processing algorithms. Here, we describe twocomplementary approaches for (a) revealing the acoustic cues used by aparticipant in a /d/-/g/ categorization task in noise and (b) measuring therelative contributions of these cues to decision. These two approaches involvenatural speech recordings altered by the addition of a “bump noise.” The bumpswere narrowband bursts of noise localized on the spectrotemporal locations ofthe acoustic cues, allowing the experimenter to manipulate the consonantpercept. The cue-weighting strategies were estimated for three groups ofparticipants: 17 NH listeners, 18 HI listeners with high-frequency loss, and 15HI listeners with flat loss. HI participants were provided with individualfrequency-dependent amplification to compensate for their hearing loss. Althoughall listeners relied more heavily on the high-frequency cue than on thelow-frequency cue, an important variability was observed in the individualweights, mostly explained by differences in internal noise. Individuals withhigh-frequency loss relied slightly less heavily on the high-frequency cuerelative to the low-frequency cue, compared with NH individuals, suggesting apossible influence of supra-threshold deficits on cue-weighting strategies.Altogether, these results suggest a need for individually tailoredspeech-in-noise processing in hearing aids, if more effective speechdiscriminability in noise is to be achieved.