Temporal Resolution With a Prescriptive Fitting Formula

Abstract

Purpose Previous work using laboratory-based paradigms documented that WDRC may improve gap detection compared to linear amplification. The purpose of this study was to measure temporal resolution using WDRC fit with compression ratios set for each listener’s hearing loss. Method Nineteen adults with mild-to-moderate hearing loss fitted with WDRC or linear amplification set to a prescriptive fitting method participated in this study. Subjects detected amplitude modulations and gaps. Two noise carriers were used: narrowband (1995–2005 Hz) or broadband (100–8000 Hz). Results Small differences between WDRC and linear amplification were observed in the measures of temporal resolution. Modulation detection thresholds decreased by a mean of 0.7 dB with WDRC compared to linear amplification. This reduction was observed for both carrier types. Gap detection thresholds did not differ between the two amplification conditions. Conclusions WDRC set using a prescriptive fitting method with individualized compression ratios had a small, but statistically significant effect on measures of modulation thresholds. Differences were not observed between the two amplification conditions for the measures of gap detection. These findings contrast with previous work using fixed compression ratios, suggesting that the effect of the fitting method on the compression ratio should be considered when attempting to generalize the effect of WDRC on temporal resolution to the clinic.

Effects of Hearing Loss and Fast-Acting Compression on Amplitude Modulation Perception and Speech Intelligibility

“…Since fast-acting DRC reduces the depth of modulation in the temporal envelope, this type of processing might be able to restore the normal internal representation of the envelope in LSNHL. Brennan et al (2013) obtained MDTs with noise carriers in conditions with and without DRC for LSNHL and found higher MDTs in the conditions with DRC, consistent with the idea that DRC may compensate for recruitment. However, the study did not consider to what extent the DRC processing restored performance to the level found for listeners with NH.…”

The influence of hearing-aid compression on forward-masked thresholds for adults with hearing loss

“…Glasberg and Moore (1992) and noted that gap detection thresholds better approximated those for listeners with NH when the listeners with SNHL listened via fast (15 ms attack time, 30 ms release time) instead of slow (300 ms attack time, 3 s release time) compression. Brennan et al (2013) found reduced detectability of amplitude modulation with fast than slow compression for listeners with SNHL. The latter finding may appear to refute the argument that fast compression best restores measures of temporal resolution.…”

Exploring the Relationship Between Working Memory, Compressor Speed, and Background Noise Characteristics

“…For example, fast-acting compression (release times <200 ms) results in a compressor output with reduced modulation depth, and therefore in reduced sensitivity to the information-bearing modulations in the speech signal (e.g., Brennan, Souza, Gallun & Stecker, 2013; Greenberg & Ainsworth, 2004). Fast-acting compression may also increase similarity between the envelope modulations of the signal and the envelope modulations of a masking noise (e.g., Stone & Moore, 2008).…”