Consequences of disrupted spatial perception with hearing aids for "cocktail party" listening

Individuals with hearing loss struggle with speech understanding in multitalker ("cocktail party") situations even while wearing hearing aids. Although hearing aids provide critical amplification, they also can disrupt the spatial perception of sounds. It is not known if these disruptions contribute to the speech-recognition difficulties of hearing-aid wearers. In this study, normally hearing participants were fitted with hearing aids and performed two tasks with and without the devices. In the first task, participants localized individual words presented through loudspeakers by placing a marker on a touchscreen interface; these responses were compared to the location of the presenting loudspeaker to calculate errors in azimuth and distance. In the second task, participants were presented with a mixture of five simultaneous talkers and identified the words spoken by one target talker, defined based on its spatial location. Relative to the unaided condition, hearing aids led to increased errors in azimuth and distance and lower speech-recognition scores, which were largely attributable to selecting the wrong talker. At the individual level, speech recognition was not associated with localization in unaided or aided conditions separately, however, changes in localization errors in azimuth were associated with changes in speech recognition with hearing aids.