Inherent noise fluctuations do not universally limit speech perception across hearing conditions

Evidence

Recent work has suggested that it is not so much the overall noise energy that limits speech perception in noise, as suggested by earlier work (French and Steinberg 1947 ; Kryter 1962 ; George et al. 2008 ), but rather the energy in the inherent temporal-envelope modulations in noise (Dubbelboer and Houtgast 2008 ; Jorgensen and Dau 2011 ; Stone et al. 2011 , 2012 ; Jorgensen et al. 2013 ; Stone and Moore 2014 ). In a recent study (Oxenham and Kreft 2014 ) we examined the effects of inherent noise fluctuations in CI users. In contrast to the results from normal-hearing (NH) listeners, we found that CI users exhibited no benefit of maskers without inherent fluctuations. Further experiments suggested that the effective inherent noise envelope fluctuations were reduced in the CI users, due to the effects of current spread, or interactions between adjacent electrodes, leading to smoother temporal envelopes. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2166

Overall, the results show that the importance of inherent masker fluctuations in determining speech intelligibility in noise depends to some extent on the conditions and the listening population. It cannot be claimed that inherent masker fluctuations always limit speech perception, as the effect of the fluctuations is non-existent in CI users (Oxenham and Kreft 2014 ), and is greatly reduced in HI listeners and in NH listeners at high sound levels. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2199

Categorization

• XREF: Connects to the general theme that what degrades hearing in noise is temporal masking/interaction rather than raw energy — parallels work on simultaneous masking and modulation. — connects to: Cochlear-implant users show no sensitivity to inherent noise envelope fluctuations; Hearing-impaired listeners retain partial sensitivity to inherent noise fluctuations, unlike CI users — Dijk, Pim van, Physiology, Psychoacoustics and…, 2200; Slow envelope fluctuations up to 16 Hz predict consonant-in-noise perception. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5575 (+5 more)
• corroborated: 6 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 2166; Dijk, Pim van, Physiology, Psychoacoustics and…, 2199

Broader Connections

• Slow envelope fluctuations up to 16 Hz predict consonant-in-noise perception. #corroborates (0.85) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5575
• Processing-heavy working memory tasks correlate more strongly with noisy speech perception #expands (0.75) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1230