Some perceptual properties of consonants in multitalker babble.

Abstract

This study investigated whether consonant phonetic features or consonant acoustic properties more appropriately describe perceptual confusions among speech stimuli in multitalker babble backgrounds. Ten normal-hearing subjects identified 19 consonants, each paired with /a/, 1–19 and lui in a CV format. The stimuli were presented in quiet and in three levels of babble. Multidimensional scaling analyses of the confusion data retrieved stimulus dimensions corresponding to consonant acoustic parameters. The acoustic dimensions identified were: periodicity/burst onset, friction duration, consonant-vowel ratio, second formant transition slope, and first formant transition onset. These findings are comparable to previous reports of acoustic effects observed in white-noise conditions, and support the theory that acoustic characteristics are the relevant perceptual properties of speech in noise conditions. Perceptual effects of vowel context and level of the babble also were observed. These condition effects contrast with those previously reported for white-noise interference, and are attributed to direct masking of the low-frequency acoustic cues in the nonsense syllables by the low-frequency spectrum of the babble.