Voice intensity in 19 prospective cochlear implant candidates, all adventitiously profoundly sensorineurally deaf adult males, was investigated. For the first time with objective data, it was shown that such deaf subjects spoke with significantly increased voice intensity and with greater intensity fluctuations than normal hearing male speakers. Neither length of time of profound deafness nor history of hearing aid use significantly affected voice intensity. Based on quantitative data, rehabilitation of voice intensity problems in the adventitiously deaf is indicated.

Acoustic correlates of contrastive stress, i.e., fundamental frequency (F0), duration, and intensity, and listener perceptions of stress, were investigated in a profoundly deaf subject (RS) pre/post single-channel cochlear implant and longitudinally, and compared to the overall patterns of age-peer profoundly deaf (JM) and normally hearing subjects (DL). The stimuli were a group of general American English words in which a change of function from noun to verb is associated with a shift of stress from initial to final syllable, e.g., CON'trast versus conTRAST'. Precochlear implant, RS was unable to produce contrastive stress correctly. Hearing one day post-stimulation resulted in significantly higher F0 for initial and final stressed versus unstressed syllables. Four months post-stimulation, RS maintained significantly higher F0 on stressed syllables, as well as generalization of significantly increased intensity and longer syllable duration differences for all stressed versus unstressed syllables. Perceptually, listeners judged RS's contrastive stress placement as incorrect precochlear implant and as always correct post-cochlear implant. JM's contrastive stress was judged as 96% correct, and DL's contrastive stress placement was 100% correct. It was concluded that RS reacquired all acoustic correlates needed for appropriate differentiation of contrastive stress with longitudinal use of the cochlear implant.

No objective group data on speaking rate or speaking duration have been reported on the speech of adventitiously profoundly hearing-impaired adults. Results of the present study showed that speaking rate, i.e., number of syllables per second, was significantly slower and speaking duration was significantly longer for 25 adventitiously profoundly hearing-impaired adult male cochlear implant candidates than for 10 normal-hearing control subjects. The factors of length of time since onset of profound hearing loss and hearing aid use did not significantly affect speaking rate. Based on these objective data, a rationale and method are presented for aural rehabilitation of the profoundly hearing-impaired who exhibit speaking rate abnormalities.

Six subjects have participated in a study to determine the relationship between actual and predicted performance-intensity functions for nine conditions of high-pass, low-pass, and band-pass filtered speech. Three subjects have bilateral sensorineural hearing loss of varying degrees and etiology, one subject has a unilateral sensorineural loss and two subjects have normal hearing. All subjects were trained and tested on 72 consonant-vowel syllables recorded by two male and two female talkers. Each of the nine filtered conditions (as well as the unfiltered speech) was tested at a minimum of five different levels. Hearing loss in the normal-hearing subjects was simulated by using spectrally shaped wide-band noise to create masked thresholds similar to those of the hearing-impaired subjects. Measured intelligibility scores are compared with the predictions of Articulation Theory using modifications developed by Dugal, Braida, and Durlach [in Acoustical Factors Affecting Hearing Aid Performance and Measurement, edited by Studebaker and Hochberg, (1980)] [Research supported by NIH.]