Access to "speech glimpses" in multitalker mixtures afforded by non-linear hearing-aid gain with fast-acting compression.

Abstract

Reductions in speech audibility are more detrimental in the presence of competing sounds, where there is little redundant speech information, than in quiet. Indeed, previous results suggest that insufficient audibility of "speech glimpses" may partly explain the poor performance of listeners with hearing loss in multitalker mixtures. An implication of those results is that restoring audibility across the spectrum may be especially critical in such situations. The current study investigated whether current hearing-aid amplification strategies adequately restore the audibility of speech glimpses. Ideal time-frequency segregation was used to isolate target speech glimpses from unaided and aided speech mixtures. Intelligibility was then measured for the isolated glimpses and for the original mixtures. Participants were young adults with bilateral sensorineural hearing loss, and individualized non-linear amplification with fast-acting compression was provided using the open Master Hearing Aid. Results showed that amplification generally improved the audibility and intelligibility of the target speech glimpses, but the benefit was diminished in the mixture, suggesting that there were counteracting effects. This approach may provide a useful way to unpack positive and negative effects of hearing-aid processing in multitalker mixtures.