Accounting for normal‐hearing listeners' perceptions of syllable‐initial /d/'s spoken by hearing‐impaired talkers

Abstract

A substantial corpus of data on normal‐hearing listeners' perceptions of stop and glide consonants spoken by sensorineural hearing‐impaired talkers of widely varying speech production abilities has been collected. This report concerns the authors' first efforts to measure acoustic cues to consonants in these productions and to relate cue presence to perceptual judgments. The focus was on /d/, as produced in citation‐form /dVk/ syllables (V = /ɑ/, /æ), by ten severely through profoundly hearing‐impaired talkers representing the midrange of speech production abilities among our hearing‐impaired adults. The /dVk/ syllables, along with other syllables contrastive for the initial consonant, were presented to normal‐hearing listeners who made identification judgments for the syllable‐initial consonant and, at the same time, rated their confidence in each judgment. Acoustic analysis of the /dVk/ syllables generally revealed some form of measurable release burst at onset; however, the bursts were often abnormal for /d/ in either their onset characteristics, amplitude, duration, or spectrum. The strength and quality of the talkers' vocalic cues to /d/ idiosyncratically depended upon the identity of the syllable vowel. A token‐by‐token analysis of the perception data showed that some constellations of /d/ cues yielded relatively high identification accuracy, others yielded high confidence, but only a small subset yielded both. [Work supported by NIH and the Gallaudet Research Institute.]