Graeme Clark Collection

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    Potential and limitations of cochlear implants in children
    Dowell, R. C. ; Blamey, P. J. ; Clark, Graeme M. ( 1995)
    Multiple-channel cochlear implants have been in use with children and adolescents for 8 years. The speech perception, speech production, and language of many of these children has been investigated in some detail.l-4 There have been many predictions about factors that may affect the performance of children with implants. For instance, it has been suggested that children with a congenital loss of hearing would not have the same potential to benefit from a cochlear implant as those with an acquired loss. Similarly, it has been suggested that younger children are likely to gain more benefit from a cochlear implant because of the effect of various critical ages for language learning.5 As more results have become available, it has been our observation that the performance of any particular child with a cochlear implant does not appear to follow well-defined rules, and that generalizations about the potential of certain groups of children are likely to encounter many exceptions. We now have a large quantity of results for children using cochlear implants, and it may be possible to determine some of the factors that have a significant effect on performance. This paper will attempt to identify some of these factors by reviewing speech perception results for 100 children implanted with the Nucleus 22-channel cochlear prosthesis in Australia and speech perception results for adult patients. This analysis will use an "information processing" model of a child using a cochlear implant. That is, we will assume that a child will benefit from a cochlear implant in terms of speech perception, production, and language development, if he or she receives a maximal amount of auditory information from the environment, and is able to process this information successfully. This model divides potential limiting or predictive factors into those that affect the information presented to the auditory system (eg, implant technology, surviving auditory neurons) and those that affect the processing of this information (eg, development of central auditory pathways, amount and consistency of auditory input).
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    The University of Melbourne/Nucleus cochlear prosthesis
    Clark, Graeme M. ; Blamey, P. J. ; Brown, A. M. ; Busby, P. A. ; Dowell, R. C. ; Franz, B. K-H. ; Millar, J. B. ; Pyman, B. C. ; Shepherd, R. K. ; Tong, Y. C. ; Webb, R. L. ; Brimacombe, J. A. ; Hirshorn, M. S. ; Kuzma, J. ; Mecklenburg, D. J. ; Money, D. K. ; Patrick, J. F. ; Seligman, P. M. ( 1988)
    This is a review of research to develop the University of Melbourne/Nucleus cochlear prosthesis for patients with a profound-total hearing loss. A more complete review can be obtained in Clark et al. A prototype receiver-stimulator and multiple-electrode array developed at the University of Melbourne was first implanted in a postlingually deaf adult patient with a profound-total hearing loss on 1 August 1978. A speech processing strategy which could help this patient understand running speech, especially when combined with lipreading was developed in 1978 following initial psychophysical studies. A prototype wearable speech processor was fabricated in 1979, that could provide significant help for the first two patients in understanding running speech when used in combination with lipreading compared with lipreading alone, and it also enabled them to understand some running speech when using electrical stimulation alone. An implantable receiver-stimulator and wearable speech processor embodying the principles of the prototype devices were then produced for clinical trial by the Australian biomedical firm, Nucleus Ltd, and its subsidiaries, Cochlear Pty Ltd and Cochlear Corporation. This cochlear implant was initially clinically trialled on six patients at The Royal Victorian Eye & Ear Hospital in 1982, and shown to give similar results to those obtained with the prototype device. In view of these findings a clinical trial was carried out for a Premarket Approval Application to the US Food and Drug Administration (FDA), and extended to a number of centres in the US, Canada, and West Germany. This clinical trial confirmed that patients could understand running speech when electrical stimulation was combined with lipreading, and that some patients could also understand running speech when using electrical stimulation alone. Today, more than 600 patients world-wide are using cochlear implants developed from the research described in this paper.
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    An acoustic model of a multiple-channel cochlear implant
    Blamey, P. J. ; Dowell, R. C. ; Tong, Y. C. ; Clark, Graeme M. ( 1984)
    Abstract not available due to copyright.
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    Speech processing studies using an acoustic model of a multiple-channel cochlear implant
    Blamey, P. J. ; Dowell, R. C. ; Tong, Y. C. ; Brown, A. M. ; Luscombe, S. M. ; Clark, Graeme M. ( 1984)
    Abstract not available due to copyright.