Graeme Clark Collection

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    Cochlear implants in children, adolescents, and prelinguistically deafened adults: speech perception
    Dawson, Pam. W ; Blamey, Peter J. ; Rowland, Louise C. ; Dettman, Shani J. ; Clark, Graeme M. ; Busby, Peter A. ; Brown, Alison M. ; Dowell, Richard C. ; Rickards, Field W. ( 1992)
    A group of 10 children, adolescents, and prelinguistically deafened adults were implanted with the 22-electrode cochlear implant (Cochlear Pty Ltd) at the University of Melbourne Cochlear Implant Clinic and have used the prosthesis for periods from 12 to 65 months. Postoperative performance on the majority of closed-set speech perception tests was significantly greater than chance, and significantly better than preoperative performance for all of the patients. Five of the children have achieved substantial scores on open-set speech tests using hearing without lipreading. Phoneme scores in monosyllabic words ranged from 30% to 72%; word scores in sentences ranged from 26% to 74%. Four of these 5 children were implanted during preadolescence (aged 5:5 to 10:2 years) and the fifth, who had a progressive loss, was implanted during adolescence (aged 14:8 years). The duration of profound deafness before implantation varied from 2 to 8 years. Improvements were also noted over postoperative data collection times for the younger children. The remaining 5 patients who did not demonstrate open-set recognition were implanted after a longer duration of profound deafness (aged 13:11 to 20:1 years). The results are discussed with reference to variables that may affect implant performance, such as age at onset of loss, duration of profound loss, age at implantation, and duration of implantation. They are compared with results for similar groups of children using hearing aids and cochlear implants.
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    Speech perception, production and language results in a group of children using the 22-electrode cochlear implant
    Blamey, P. J. ; Dawson, P. W. ; Dettman, S. J. ; Rowland, L. C. ; Brown, A. M. ; Busby, P. A. ; Dowell, R. C. ; Rickards, F. W. ; Clark, Graeme M. ( 1992)
    Five children out of a group of nine (aged 5.5 to 19.9 years) implanted with the 22-electrode cochlear implant (Cochlear Ply. Ltd.) have achieved substantial scores on open-set speech tests using hearing without lipreading. Phoneme scores for monosyllabic words ranged from 40% to 72%. Word scores in sentences ranged from 26% to 74%. Four of these five children were implanted during preadolescence. The fifth child, who had a progressive loss and was implanted during adolescence after a short period of very profound deafness, scored highest on all speech perception tests. The remaining four children who did not demonstrate open-set recognition were implanted during adolescence after a long duration of profound deafness. Post-operative performance on closed-set speech perception tests was better than pre-operative performance for all children. Improvements in speech and language assessments were also noted. These improvements tended to be greater for the younger children. The results are discussed with reference to variables which may contribute to successful implant use: such as age at onset, duration of profound hearing loss, age at implantation, aetiology, educational program, and the type of training provided.
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    Cochlear implants in children, adolescents, and prelinguistically deafened adults: speech perception
    Dawson, Pam W. ; Blamey, Peter J. ; Rowland, Louise C. ; Dettman, Shani J. ; Clark, Graeme M. ; Busby, Peter A. ; Brown, Alison M. ; Dowell, Richard C. ; Rickards, Field W. ( 1992)
    A group of 10 children, adolescents, and prelinguistically deafened adults were implanted with the 22-electrode cochlear implant (Cochlear Ply Ltd) at the University of Melbourne Cochlear Implant Clinic and have used the prosthesis for periods from 12 to 65 months. Postoperative performance on the majority of closed-set speech perception tests was significantly greater than chance, and significantly better than preoperative performance for all of the patients. Five of the children have achieved substantial scores on open-set speech tests using hearing without lipreading. Phoneme scores in monosyllabic words ranged from 30% to 72%; word scores in sentences ranged from 26% to 74%. Four of these 5 children were implanted during preadolescence (aged 5:5 to 10:2 years) and the fifth, who had a progressive loss, was implanted during adolescence (aged 14:8 years). The duration of profound deafness before implantation varied from 2 to 8 years. Improvements were also noted over postoperative data collection times for the younger children. The remaining 5 patients who did not demonstrate open-set recognition were implanted after a longer duration of profound deafness (aged 13:11to 20:1 years). The results are discussed with reference to variables that may affect implant performance, such as age at onset of loss, duration of profound loss, age at implantation, and duration of implantation. They are compared with results for similar groups of children using hearing aids and cochlear implants.
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    Electrode position, repetition rate, and speech perception by early-and-late-deafened cochlear implant patients
    Busby, P. A. ; Tong, Y. C. ; Clark, Graeme M. ( 1993)
    Psychophysical and speech perception studies were conducted on eight patients using the 22electrode cochlear implant manufactured by Cochlear Pty. Ltd. Four early-deafened patients became deafened at 1-3 years of age and were implanted at 5-14 years of age. Four late-deafened (postlingual adult) patients became deafened at 38-47 years of age and were implanted at 42-68 years of age. Psychophysical studies measured the discrimination of trajectories with time-varying electrode positions and repetition rates. Speech perception studies measured performance using two speech coding strategies: a multi-electrode strategy which coded the first and second formant frequencies, the amplitudes of the two formants, and the fundamental frequency; and a single-electrode strategy which coded the amplitudes of the first and second formants, and the fundamental frequency. In general, the four late-deafened patients and one early-deafened patient were more successful than the other three early-deafened patients in the discrimination of electrode position trajectories and in speech perception using the multi-electrode strategy. Three of the four late-deafened patients were more successful than the early-deafened patients in the discrimination of repetition rate trajectories. Speech perception performance in the single-electrode strategy was closely related to performance in repetition rate discrimination. The improvement in speech perception performance from the single-electrode to multi-electrode strategy was consistent with successful performance in electrode discrimination.
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    Results of speech perception and speech production training for three prelingually deaf parents using a multiple-electrode cochlear implant
    Busby, P. A. ; Roberts, S. A. ; Tong, Y. C. ; Clark, Graeme M. ( 1991)
    Five studies were conducted to measure changes in the perception and production of selected speech targets, with training, in three prelingually deaf patients. The two adults and one adolescent were implanted with the Cochlear (Nucleus) multiple-electrode prosthesis. The studies were perception and production of nasal consonants; perception of syllable-final consonants; perception and production of alveolar consonants; auditory-visual perception of alveolar consonants; and perception and production of vowels. Perceptual data were collected in the audition (implant)-alone condition, except for the auditory visual perception of alveolar consonants where the audition-alone, vision-alone, and auditory-visual conditions were used. Speech perception data in the audition-alone condition were also collected from four postlingually deaf adult implant patients, without training, to indicate differences between the two classes of patients. The three prelingually deaf patients generally showed some improvements in speech production. In perception, improvements were recorded only for individual patients in some studies. The performance of the adolescent was better than that of the two adults in all cases. The perceptual performance of the postlingually deaf patients was superior to that of the prelingually deaf patients in all cases.