Across-frequency processing of modulation phase differences in hearing-impaired listeners.

Two experiments tested the influence of hearing impairment (HI) on representing across-frequency temporal coherence. In one experiment, HI listeners demonstrated similar abilities to normal-hearing listeners in detecting across-frequency differences in modulation phase. In another, spectral-shape discrimination was detrimentally affected by modulation phase disparities imposed on spectral components. Spectral-shape discrimination by HI listeners was less influenced by the disparities, suggesting that hearing loss alters the representation of envelope phase. Results suggest that multiple approaches may be necessary to determine alterations associated with hearing loss—detection tasks may not be sufficient to elucidate distortions to temporal envelope associated with hearing loss.