Differential metrics can separate cochlear gain loss from temporal coding deficits in hearing loss
Evidence
AM thresholds to pure-tone carriers (4 kHz) in normal-hearing listeners depended on temporal coding fidelity. AM thresholds in hearing-impaired listeners were normal, indicating that reduced cochlear gain may counteract how reduced temporal coding fidelity degrades AM thresholds. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5870
If the NB condition reflects a temporal coding deficit, then it appeared not to dictate performance in the BB condition for the HI listeners, suggesting that perhaps the overall loss of compression due to cochlear gain loss would enhance modulation sensitivity such that a fixed-level BB noise did not degrade performance substantially, despite the reduced temporal coding observed from the EFR measures. It is too early to make strong conclusions regarding the underlying mechanisms based on the present dataset, as additional data and additional metrics that reflects the individual listeners cochlear compression should be added to further tease apart the psychoacoustic results. In this respect, both categorical loudness scaling metrics and DPOAE compression slope estimates could be included. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5903
Categorization
- QUESTION: Mechanism unclear — how does reduced gain counteract envelope-coding degradation in AM thresholds? Worth chasing for the physiology links.
- corroborated: 3 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 5870; Dijk, Pim van, Physiology, Psychoacoustics and…, 5903
- XREF: connects to: Cochlear hearing loss raises interaural time discrimination thresholds independent of age — Dijk, Pim van, Physiology, Psychoacoustics and…, 817; Lost cochlear compression degrades speech formant coding in hearing-impaired listeners; Wiener-kernel methods can reveal central gain changes in brainstem after peripheral damage (+8 more)
Broader Connections
- The audiogram cannot predict which hearing-impaired listeners have temporal processing deficits
#expands(0.85) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1088 - Hearing loss impairs frequency selectivity beyond what stimulus level differences explain.
#expands(0.75) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 558