AIDED SPEECH RECOGNITION ABILITIES OF ADULTS WITH A SEVERE OR SEVERE-TO-PROFOUND HEARING-LOSS

Adults with severe or severe-to-profound hearing losses constitute bet ween 11% and 13.5% of the hearing-impaired population. A detailed inve stigation of the speech recognition of adults with severe (n = 20) or severe-to-profound (n = 14) hearing loss was conducted at The Universi ty of Melbourne. Each participant took part in a series of speech reco gnition tasks while wearing his or her currently fitted hearing aid(s) . The assessments included closed-set tests of consonant recognition a nd vowel recognition, combined with open-set tests of monosyllabic wor d recognition and sentence recognition. Sentences were presented in qu iet and in noise at +10 dB SNR to replicate an environment more typica l of everyday listening conditions. Although the results demonstrated wide variability in performance, some general trends were observed. As expected vowels were generally well perceived compared with consonant s. Monosyllabic word recognition scores for both the adults with a sev ere hearing impairment (M = 67.2%) and the adults with a severe-to-pro found hearing impairment (M = 38.6%) could be predicted from the segme ntal tests, with an allowance for lexical effects. Scores for sentence s presented in quiet showed additional linguistic effects and a signif icant decrease in performance with the addition of background noise (f rom 82.9% to 74.1% for adults with a severe hearing loss and from 55.8 % to 34.2% For adults with a severe-to-profound hearing loss). Compari sons were made between the participants and a group of adults using a multiple-channel cochlear implant. This comparison indicated that some adults with a severe or severe-to-profound hearing loss may benefit f rom the use of a cochlear implant. The results of this study support t he contention that cochlear implant candidacy should not rely solely o n audiometric thresholds.