Sensorineural hearing loss reduces contrast in F0-synchronized neural rates across frequency

Evidence

In the impaired ear, the F0-synchronized rate profile is affected by several factors: Reduced synchrony capture decreases the dominance of a single harmonic near BF on the response. Elevated thresholds also reduce the effect of rate saturation, resulting in increased F0-synchrony. Wider peripheral tuning results in a wider-band envelope with reduced F0 amplitude. In general, sensorineural hearing loss reduces the contrast in AN F0-synchronized rates across BF. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5469

The dominant components for model AN fibres with SNHL simulated by outer and inner hair cell dysfunction are shown in Fig. 2f . Physiological studies have shown that synchrony capture is weaker in these fibres (Miller et al. 1997 ). The model response illustrates reduced synchrony capture, especially to F2 (Fig. 2f , red arrow), even for the mild hearing loss in this simulation. The reduced synchrony capture is more evident in the pattern of synchrony to F0, which extends across all regions where there is sufficient energy to drive the neurons (Fig. 2f , black arrow). Thus, the profile of F0-synchronized rates differs qualitatively between the impaired and the healthy AN populations. For BFs tuned between F1 and F2 (green arrow), the response to F0 (black arrow) is reduced in the impaired nerve, whereas in the BF regions of F1 and of F2 (orange arrows), the response to F0 is increased in the impaired nerve. The net effect of SNHL is a reduction in the contrast of the F0-synchronized rates across BF. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5488

In response to voiced speech sounds, auditory-nerve (AN) fibres phase-lock to harmonics near best frequency (BF) and to the fundamental frequency (F0) of voiced sounds. Due to nonlinearities in the healthy ear, phase-locking in each frequency channel is dominated either by a single harmonic, for channels tuned near formants, or by F0, for channels between formants. The alternating dominance of these factors sets up a robust pattern of F0-synchronized rate across best frequency (BF). … In general, sensorineural hearing loss reduces the contrast in AN F0-synchronized rates across BF. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5469

Categorization

• XREF: Connects to the broader theme that hearing loss degrades temporal coding (declining phase-locking, wider tuning) — the very cues that auditory nerve fibres rely on. — connects to: Wider peripheral tuning from hearing loss suppresses low-frequency fluctuation amplitude; Hearing loss impairs frequency selectivity beyond what stimulus level differences explain. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 558; Hearing loss reduces cochlear suppression and compressive nonlinearity together — Dijk, Pim van, Physiology, Psychoacoustics and…, 3878 (+2 more)
• corroborated: 7 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 5469; Dijk, Pim van, Physiology, Psychoacoustics and…, 5488

Broader Connections

• Wider peripheral tuning from hearing loss suppresses low-frequency fluctuation amplitude #corroborates (0.85)
• Hearing loss impairs frequency selectivity beyond what stimulus level differences explain. #corroborates (0.80) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 558
• Sensorineural hearing loss compresses the full loudness range into fewer decibels #expands (0.78) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 838
• Hearing loss reduces cochlear suppression and compressive nonlinearity together #complicates (0.75) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3878