Discrimination of formant‐like glides in gated noise: Effect of sensation level.

Abstract

Listeners with sensorineural hearing loss (SNHL) do not experience masking release for speech in fluctuating noise, as normal‐hearing listeners do. One hypothesis suggests dip listening may be difficult because frequency glides, or speech formant transitions, may be difficult to discriminate at low sensation levels when in the presence of fluctuating noise. Normal‐hearing listeners were tested for their ability to discriminate 100‐ms frequency glides with center frequencies of 800 and 2500 Hz. They were tested in quiet and in the presence of 500‐ms of 8‐Hz square‐wave gated broadband noise at a signal‐to‐noise ratio of −10 dB. Listeners were tested at low (10–15 dB SL) and moderate (30–40 dB SL) signal levels. Preliminary results suggest that glide discrimination thresholds (measured as % change) are similar for low‐ and moderate‐level stimuli in quiet; glide thresholds are poorer in gated noise than in quiet; and glide thresholds are poorest when low‐level stimuli were presented in gated noise. These results suggest that when formants or glides are presented at low levels and in gated noise, discrimination abilities may be reduced. Implications for understanding masking release for speech by listeners with hearing loss will be discussed. [Work supported by NIH 5R01DC008306.]