Perceptual Adaptation to Room Acoustics and Effects on Speech Intelligibility in Hearing-Impaired Populations

Recent evidence suggests that brief listening exposure to a reverberant room environment can improve closed-set speech intelligibility in that same environment. For normal-hearing populations, this room adaptation effect can result in improvements in intelligibility of as much as 20%, but depends strongly on the reverberation time of the room, and appears to require binaural input. Because poor speech intelligibility in reverberation is a common complaint for hearing-impaired listeners, it is important to determine how room adaptation might impact speech intelligibility for hearing-impaired populations. Here, room adaptation was quantified for a sample of listeners with sensorineural hearing loss that varied in severity and configuration. Speech reception thresholds (SRTs) were measured both with and without prior listening exposure to the room environment. Headphone-based auralization techniques were used to simulate the acoustics of various listening rooms, ranging from anechoic to highly reverberant space (broadband T₆₀ = 3 s). Although SRTs both with and without prior room exposure were found to be generally elevated relative to normal-hearing listeners, the room adaptation effect, as defined by the relative decrease in SRT with room exposure, was comparable on average to that observed for normal-hearing listeners. This result is consistent with the view that room adaptation effects result from central auditory processing mechanisms.