Travelling wave delay of the basilar membrane in age-related hearing loss.
Level 4 - case-series / case-control
Cross-sectional comparative study
PubMed 41521811 · doi:10.1017/S0022215125104064
What was done
Researchers evaluated tympanic membrane electrocochleography recordings at 0.5 and 4 kHz across 85 ears from 49 adults using a cross-sectional design. Participants were categorized into four groups: older adults with hearing loss (n = 22 ears), older adults with normal hearing (n = 18 ears), younger adults with hearing loss (n = 19 ears), and younger adults with normal hearing (n = 26 ears). Frequency-specific action potential latencies and travelling wave delay were compared across groups.
What was found
Action potential latencies were significantly influenced by age and hearing loss. At 0.5 kHz, older adults with hearing loss exhibited the longest latencies (p < 0.001). At 4 kHz, latencies differed between older adults with hearing loss and older adults with normal hearing (p = 0.027). Travelling wave delay differed significantly across groups (p < 0.001), being shortest in younger adults with normal hearing and longest in older adults with hearing loss. Absolute numerical latencies, delay durations, and effect sizes were not provided in the abstract.
Why it matters
This study demonstrates that ageing and hearing loss reduce basilar membrane travelling wave velocity, suggesting that electrocochleographic travelling wave delay could serve as a functional marker for early cochlear transmission deficits.
Limits
The study relies on a small sample size (49 participants across four groups) and a cross-sectional design that cannot determine causality or longitudinal progression. The analysis uses ears rather than individuals as the primary sample unit without clear adjustment for within-subject correlation. Key quantitative data, including baseline audiometric criteria, age thresholds, exact latencies, and variance, are omitted from the abstract.
Cited by
- supports With aging, the basilar membrane in the inner ear becomes more rigid and temporal auditory processing slows down.