Temporal Effects of Preceding Band-Pass and Band-Stop Noise on the Recognition of Voiced Stops

A previous study showed that the scores on recognition of plosive-vowel syllables improve with noise preceding the speech, compared to noise gated on and off simultaneously with the signal [1]. To investigate this question further, the present study examined the influence of masker bandwidth, masker and signal spectral separation and masker level on the recognition scores of band-pass filtered speech stimuli for different durations of the preceding noise. When the signal onset was delayed 200ms from the masker onset, its recognition improved, compared with gated noise. A smaller increase was observed in the performance for longer delays. The same amount of improvement in the recognition of the syllables (around 28%) was obtained for band-pass and band-stop preceding noise. The beneficial effects of these preceding maskers on the scores on recognition of the speech stimuli used in this study are similar to those obtained in the psychophysical studies on “overshoot ” and “auditory enhancement ” phenomena. PACS no. 43.71.Gv 1