SPEECHREADING SUPPLEMENTED WITH AUDITORILY PRESENTED SPEECH ELEMENTS IN THE PROFOUNDLY HEARING-IMPAIRED

For many profoundly hearing-impaired listeners (hearing loss >90 dB HL ) speechreading is the most important means of communication; amplifie d speech may provide, at best, additional information to speechreading . In order to improve audiovisual communication, three speech pattern elements comprising voice-fundamental frequency (f(0)), the first form ant (F-1), and the first and the second formant (F1F2) were presented as supplements to speechreading. A fourth condition consisted of a nat ural speech supplement, a fifth of speechreading only Twenty subjects were tested; all audiovisual speech scores were significantly higher t han the purely visual scores. Audiovisual scores for amplified, natura l speech were significantly higher than those for f(0) and F1F2 coded speech. Scores for natural speech and for F-1 coded speech were not si gnificantly different. The relations between the increase in audiovisu al speech scores over the visual scores and measures of difference lim en for frequency (DLf) and gap detection were not clear. The most prom inent correlations with the speech scores were found for the DLf at 12 5 Hz and for gap detection.