A review of speech masking release for hearing-impaired listeners with near-normal perception of speech in unmodulated noise maskers

For normal-hearing listeners, intelligibility is higher for speech in fluctuating than in steady noise, a phenomenon called masking release. This difference is typically reduced for hearing-impaired listeners. It has recently been suggested (Bernstein and Grant, 2009) that the limited benefit for hearing-impaired listeners reported previously results largely from the higher signal-to-noise ratio at which intelligibility was estimated for those listeners in the baseline condition using steady noise. Several studies are reviewed in which normal-hearing (NH) and hearing-impaired (HI) listeners were tested at identical signal-to-noise ratios; these studies showed limited benefit from noise fluctuations for hearing-impaired listeners, even those with mild losses, despite normal performance in steady noise. Thus, the reduced masking release cannot be explained entirely by the signal-to-noise ratio at which the measurements were made. It also cannot be explained by the amount and configuration of the hearing losses, frequency region, speech material Table: Listener groups, materials, and procedures for each study. Left part: details of studies reporting speech identification performance measured at fixed signal-to-noise ratios (SNRs). The group data either showed no significant difference in identification of speech in steady noise between NH and HI listeners, or some individual HI listeners performed as well as the NH listeners. Right part: details of studies in which speech reception thresholds (SRTs) were measured. SRTs for speech in steady noise did not differ significantly for NH and HI listeners. Review Acknowledgments & References A. Léger, B.C.J. Moore and C. Lorenzi were supported by a grant from the Royal Society (International Joint Project, 2009R3). A. Léger was supported by DualPro Program 7FP-SME222291, and by a CIFRE grant from ANRT and Neurelec. B.C.J. Moore was supported by the MRC (UK). C. Lorenzi was supported by the ANR Presbycusis and RTRS Foundation. Bacon, S. P., Opie, J. M. , and Montoya, D. Y. (1998). "The effects of hearing loss and noise masking on the masking release for speech in temporally complex backgrounds," Journal of Speech, Language and Hearing Research 41, 549-563. Bernstein, J. G. W. , and Grant, K. W. (2009). "Auditory and auditory-visual intelligibility of speech in fluctuating maskers for normal-hearing and hearing-impaired listeners," J. Acoust. Soc. Am. 125, 3358-3372. Eisenberg, L. S. , Dirks, D. D. , and Bell, T. S. (1995). "Speech recognition in amplitude-modulated noise of listeners with normal and listeners with impaired hearing," J. Speech Hear. Res. 38, 222-233. Grose, J. H. , Mamo, S. K. , and Hall, J. W. , 3rd (2009). "Age effects in temporal envelope processing: speech unmasking and auditory steady state responses," Ear. Hear. 30, 568-575. Jin, S. H. , and Nelson, P. B. (2006). "Speech perception in gated noise: the effects of temporal resolution," J. Acoust. Soc. Am. 119, 3097-3108. Strelcyk, O. , and Dau, T. (2009). "Relations between frequency selectivity, temporal fine-structure processing, and speech reception in impaired hearing," J. Acoust. Soc. Am. 125, 3328-3345. Stuart, A. , and Phillips, D. P. (1996). "Word recognition in continuous and interrupted broadband noise by young normal-hearing, older normal-hearing and presbyacusic listeners," Ear Hear. 17, 478-489. Takahashi, G. A. , and Bacon, S. P. (1992). "Modulation detection, modulation masking, and speech understanding in noise in the elderly," J. Speech Hear. Res. 35, 1410-1421. J & N C Vs