Graeme Clark Collection

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    The progress of children using the multichannel cochlear implant in Melbourne
    Cowan, R. S. C. ; Dowell, R. C. ; Hollow, R. ; Dettman, S. J. ; Rance, G. ; Barker, E. J. ; Sarant, J. Z. ; Galvin, K. L. ; Webb, R. C. ; Pyman, B. C. ; Cousins, V. C. ; Clark, Graeme M. ( 1995)
    Multi-channel cochlear implantation in children began in Australia in 1985 and there are now close to 4000 profoundly deaf children and adolescents using the Australian implant system around the world. The aim of the implant procedure is to provide adequate hearing for speech and language development through auditory input. This contrasts with the situation for adults with acquired deafness where the cochlear implant aims to restore hearing for someone with well-developed auditory processing and language skills. As with adults, results vary over a wide range for children using the Multi-channel implant. Many factors have been suggested that may contribute to differences in speech perception for implanted children. In an attempt to better understand these factors, the speech perception results for children implanted in Melbourne were reviewed and subjected to statistical analysis. This has indicated that the amount of experience with the implant and the length of sensory deprivation are strongly correlated with perceptual results. This means that younger children are likely to perform better with an implant and that a number of years of experience are required for children to reach their full potential. The results have also indicated that educational placement and management play a crucial role in children reaching their potential. Overall, 60% of the children and adolescents in the study have reached a level of open-set speech understanding using the cochlear implant without lipreading.
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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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    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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    Speech perception benefits for implanted children with preoperative residual hearing [Abstract]
    Hollow, R. ; Rance, G. ; Dowell, R.C. ; Pyman, B. ; Clark, Graeme M. ; Cowan, R. S. C. ; Galvin, K. L. ; Barker, E. J. ; Sarant, J. Z. ; Dettman, S. ( 1995)
    Since the implantation of the first children with the Nucleus 22-channel cochlear prosthesis in Melbourne in 1985, there has been rapid expansion in the number of implanted children world-wide. Improved surgical technique and experience in paediatric assessment and management have contributed to a trend to implant very young children. At the same time there has also been continuing development of improved speech processing strategies resulting in greater speech perception benefits. In the Melbourne program, over 60% of children obtain significant scores on open-set word and sentence tests using their cochlear implant alone without the aid of lipreading. As parents and professionals have become aware of these improved benefits to speech perception benefits in profoundly deaf children, there have been requests to consider implanting severely-to-profoundly deaf children. In these children with higher levels of residual hearing, only those children with poorer-than-expected performance on speech perception tests using hearing aids have been considered for surgery. A number of such cases have now been implanted in the Melbourne program. The speech perception benefits for this group are reported and are being compared with benefits for the profoundly deaf group of children.
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    Results of multichannel cochlear implantation in very young children [Abstract]
    Galvin, K. ; Clark, Graeme M. ; Dettman, S. ; Dowell, R. ; Barker, E. ; Rance, G. ; Hollow, R. ; Cowan, R. ( 1995)
    Most researchers and clinicians working in the cochlear implant field have assumed that profoundly deaf children will have a better prognosis in terms of speech perception, speech production and language development. if implanted at as young an age as possible. However, it has been difficult to gather direct evidence for this hypothesis due to the problems in assessing children under the age of five years with formal tests. Recent results with older children have supported the view that early implantation may provide the optimal outcome in most cases. The implantation of very young children raises two areas of concern that do not apply in adults and older children: accurate assessment of degree of hearing loss and auditory potential; and postoperative assessment of outcomes. This paper will describe research results from the University of Melbourne which address these issues and present results for children implanted as young as eighteen months of age.