The oral speech intelligibility of hearing-impaired talkers

Recordings were made of 10 hearing-impaired adolescents speaking sentences of systematically different phonologic and syntactic structure. Tapes containing these sentences were played to both experienced and inexperienced listeners in different conditions: in the absence versus in the presence of a verbal context; by auditory versus audio-visual presentation; with one versus two presentations of each sentence token. The responses of the listeners were scored and averaged for each subject, condition, and type of sentence. Significant differences were observed between (1) simple sentences and those which are complicated either by consonant clusters, polysyllabic words, or complex syntax; (2) experienced and inexperienced listeners; (3) sentences in and out of context, and (4) sentences heard and seen as opposed to merely heard. The results are discussed with reference to measurement of the intelligibility of the speech of hearing-impaired individuals.