Consonant-feature transmission as a function of presentation level in hearing-impaired listeners.

Normal-hearing listeners and listeners with a high-frequency sensorineural hearing loss identified 17 consonants as part of a consonant-vowel syllable with /a/ or /i/ as the vowel. The syllables were set at presentation levels of 10 to 65 dB re thresholds at 1000 Hz. The performance for the consonants comprising each of 11 a priori acoustic-phonetic features improved directly with increases in presentation level for both subject groups, but was better in the /a/ than in the /i/ context. The performance of the hearing-impaired listeners was significantly poorer than the performance of the normal-hearing listeners only for the higher-frequency features of frication and sibilance. The lower-frequency features of voicing and sonorance were reflected in the confusion matrices of hearing-impaired listeners at presentation levels of 10 and 20 dB; only at 35 to 65 dB were higher-frequency features transmitted in the confusion matrices of this group.