Investigating the contribution of peripheral hearing sensitivity, central auditory factors, and cognitive factors on the recognition of time-compressed speech.
Level 4 - case-series / case-control
Cross-sectional observational study comparing age and hearing cohorts
PubMed 42556074 · doi:10.1016/j.heares.2026.109765
What was done
Electrophysiological, cognitive, and behavioral assessments were evaluated across three groups: 30 younger normal-hearing adults, 32 older normal-hearing adults, and 26 older hearing-impaired adults (total n = 88). Subcortical envelope-following responses to monosyllabic words and cortical envelope tracking to continuous speech were measured at 0% and 40% time compression. Cognitive function was assessed with the NIH Toolbox, and behavioral time-compressed sentence recognition was measured adaptively to find the compression ratio yielding 50% accuracy.
What was found
Younger adults demonstrated stronger subcortical envelope encoding than older adults, and phase-locking decreased under time compression across all groups. Cortical envelope tracking was higher in older adults (both normal-hearing and hearing-impaired) compared to younger adults, and tracking increased with time compression. Younger participants showed superior processing speed and tolerated higher time-compression ratios for 50% accuracy. Audiometric thresholds, cortical envelope tracking to natural-rate speech, and processing speed significantly predicted speech recognition performance. The abstract reports no numerical values, test statistics, or p-values.
Why it matters
This study shows how peripheral hearing, cortical tracking, and cognitive processing speed independently contribute to speech-understanding deficits at fast speaking rates. It suggests that cortical envelope tracking aids recognition primarily when acoustic temporal cues are preserved.
Limits
The study relies on a cross-sectional design with a moderate sample size (n = 88 across three groups), limiting causal inference regarding aging trajectories. The abstract provides no exact quantitative effect sizes, confidence intervals, or p-values, and testing was conducted without competing background noise.
Cited by
- supports With aging, the basilar membrane in the inner ear becomes more rigid and temporal auditory processing slows down.