Narrowband noise disrupts amplitude modulation detection in cochlear neuropathy more than broadband noise does.

Evidence

Even though a temporal coding deficit may influence auditory perception, it is currently not known how cochlear neuropathy interacts with the cochlear gain loss aspect of hearing loss, or whether it is equally important for auditory perception. On the one hand, AM detection is expected to improve when cochlear compression is reduced (Moore et al. 1996 ), while cochlear neuropathy may degrade temporal coding fidelity to temporal envelopes (Bharadwaj et al. 2014 , 2015 ). To study the interaction between these components, and to quantify contributions in listeners that may suffer from both aspects of hearing loss, we tested amplitude-modulation detection (100 Hz) in quiet and in the presence of noise maskers. To force the system to rely on redundancy of coding within a single auditory filter, we determined AM thresholds in a fixed-level narrowband noise masker (NB; 40 Hz) condition. The difference between the AM threshold in quiet and with the NB noise masker might be a metric that is free from cochlear compression and sensitive to the temporal coding fidelity aspect of hearing loss. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5875

Comparison between AM detection thresholds in quiet and noise demonstrated that the mild HI listeners were heavily impacted by the NB noise. This finding is in line with the idea that the NB noise targets temporal coding fidelity within a single auditory filter, especially because 4 out of 6 HI listeners did not have EFRs at the ‑8 dB modulation depth. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5903

Categorization

• QUESTION: The interaction between reduced compression and neuropathy in AM detection is genuinely unresolved; worth chasing the study’s outcome and methods.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 5875; Dijk, Pim van, Physiology, Psychoacoustics and…, 5903