Identification of synthetic, voiced stop-consonants by hearing-impaired listeners

The identification of synthetic, voiced stop consonants changing in place of articulation was investigated in 26 normal-hearing listeners and 16 hearing-impaired listeners who reported difficulties in speech understanding, but attained high speech discrimination scores on standard test materials. Two place continua (each containing 13 stimuli changing from /ba/ to /da/ and /ga/) were employed: a continuum in which place was cued by an initial noise burst and formant transitions, and a continuum in which place was cued by formant transitions alone. All normal listeners exhibited categorical and highly consistent identification for both stimulus continua. For the hearing-impaired listeners, identification was somewhat less consistent for the burst-and-transition stimuli, and much poorer for the transition-only stimuli. Similar differences were observed when comparing the responses of 4 subjects with a unilateral hearing loss when the stimuli were presented to their normal and impaired ears, and 2 subjects with a unilateral, sudden-onset hearing loss with recovered pure-tone sensitivity.