Narrowband noise degrades AM detection mainly in listeners with reduced temporal coding
Evidence
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. Also the NH listeners showed a large variability in how the NB noise impacted their performance with a trend (p = 0.09) towards degraded AM detection performance in NB noise for those listeners with steeper EFR slopes. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5906
AM detection thresholds in background noise worsened for all listeners. Whereas the broadband noise had a variable effect on the NH listeners, the mild HI listeners were only mildly affected (Fig. 2a ). In contrast, the narrowband noise impacted AM detection performance in HI listeners significantly more strongly than did broadband noise (Fig. 2a , 2b ). This difference between the masker conditions was absent for the NH listeners. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5896
Categorization
- QUESTION: The paragraph notes an alternate brainstem modulation-coding explanation for the NB results — worth chasing whether envelope fluctuation in the masker, not fiber count, drives the effect.
- XREF: Relevant to the reader’s interest in how impaired cochlear filters interact with maskers — narrowband/masker-focused effects relate to reduced frequency selectivity in HI listeners.
- corroborated: 3 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 5906; Dijk, Pim van, Physiology, Psychoacoustics and…, 5896