Higher working-memory capacity predicts better speech-in-noise identification in hearing-impaired listeners

Evidence

A growing body of evidence from studies using mainly older hearing-impaired (HI) listeners indeed confirms that higher WMC is related to better unaided and aided speech-in-noise (SiN) identification, with correlation coefficients frequently exceeding 0.50 (Lunner 2003 ; Foo et al. 2007 ; Lunner and Sundewall-Thorén 2007 ; Arehart et al. 2013 ). In addition, high-WMC listeners were less affected by signal distortion introduced by hearing-aid processing (e.g. frequency or dynamic-range compression). — Dijk, Pim van, Physiology, Psychoacoustics and…, 1124

However, Füllgrabe et al. ( 2015 ) recently failed to observe a link between Reading-Span scores and SiN identification in older listeners (≥ 60 years) with audiometrically NH (≤ 20 dB HL between 0.125 and 6 kHz), using a range of target speech (consonants and sentences), maskers (unmodulated and modulated noise, interfering babble), and signal-to-noise ratios (SNRs). — Dijk, Pim van, Physiology, Psychoacoustics and…, 1124

Confirming previous results for audiometrically NH listeners (Füllgrabe et al. 2015 ), Reading-Span and SIN identification scores showed a significant decline with age, with Pearson’s r = ‑0.59 and ‑0.68 (both p ≤ 0.001, one-tailed), respectively. The scatterplot in Fig. 2 shows that, considering all ages, performances on the tasks were significantly related to each other (r = 0.64, p ≤ 0.001, one-tailed). This association remained significant after partialling out the effects of age and PTA (r = 0.39, p ≤ 0.001, one-tailed), contrasting with the results of Besser et al. ( 2012 ), using a cohort including only a few (N = 8) older (≥ 60 years) participants, but being roughly consistent with those reported by Koelewijn et al. ( 2012 ) for a cohort comprised of middle-aged and older (≥ 40 years) participants (see Fig. 1a ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 1146

Categorization

• XREF: Links to the Ease of Language Understanding model cited in the same chapter and to the reader’s interest in cognition in normal hearing as counterpoint. — connects to: Working memory correlates with speech-in-noise performance only in middle-aged and older normal-hearing listeners — Dijk, Pim van, Physiology, Psychoacoustics and…, 1120; Working memory capacity explains under two percent of speech-in-noise variance in young listeners. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1123; Processing-heavy working memory tasks correlate more strongly with noisy speech perception — Dijk, Pim van, Physiology, Psychoacoustics and…, 1230 (+3 more)
• QUESTION: This null result complicates the Ease of Language Understanding model — under what conditions does working memory actually engage? Worth chasing the boundary conditions.
• corroborated: 10 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 1124; Dijk, Pim van, Physiology, Psychoacoustics and…, 1146

Broader Connections

• Processing-heavy working memory tasks correlate more strongly with noisy speech perception #expands (0.85) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1230
• Working memory capacity explains under two percent of speech-in-noise variance in young listeners. #qualifies (0.82) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1123
• Mixed findings about working memory and speech-in-noise stem from task-specific WM engagement #complicates (0.80)
• Working-memory capacity predicts speech understanding only in linguistically complex listening tasks #qualifies (0.78) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1156