Graeme Clark Collection

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    Introduction: International Cochlear Implant, Speech and Hearing Symposium - Melbourne 1994
    Clark, Graeme M. ; Cowan, Robert S. C. ( 1995)
    The International Cochlear Implant Speech and Hearing Symposium - Melbourne 1994 covered a wide range of presentations in a number of disciplines. The scientific program included 287 oral presentations and 40 posters, presented to a total of 456 delegates from 38 countries. This was a considerable expansion in the number and range of presentations from the first international conference held in Melbourne in 1985 (Ann Otol Rhinal Laryngal 1987;96[suppl 128]). This growth highlights the importance of the discipline and the advances being made in this area.
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    Speech perception in children using the advanced Speak speech-processing strategy
    Cowan, R. S. C. ; Brown, C. ; Whitford, L. A. ; Galvin, K. L. ; Sarant, J. Z. ; Barker, E. J. ; Shaw, S. ; King, A. ; Skok, M. ; Seligman, P. M. ; Dowell, R. C. ; Everingham, C. ; Gibson, W. P. R. ; Clark, Graeme M. ( 1995)
    The Speak speech-processing strategy, developed by the University of Melbourne and commercialized by Cochlear Pty Limited for use in the new Spectra 22 speech processor, has been shown to provide improved speech perception for adults in both quiet and noisy situations. The present study evaluated the ability of children experienced in the use of the Multipeak (Mpeak) speech-processing strategy (implemented in the Nucleus Minisystem-22 cochlear implant) to adapt to and benefit from the advanced Speak speech-processing strategy (implemented in the Nucleus Spectra 22 speech processor). Twelve children were assessed using Mpeak and Speak over a period of 8 months. All of the children had over 1 year's previous experience with Mpeak, and all were able to score significantly on open-set word and sentence tests using the cochlear implant alone. Children were assessed with both live-voice and recorded speech materials, including Consonant-Nucleus-Consonant monosyllabic words and Speech Intelligibility Test sentences. Assessments were made in both quiet and in noise. Assessments were made at 3-week intervals to investigate the ability of the children to adapt to the new speech-processing strategy. For most of the children, a significant advantage was evident when using the Speak strategy as compared with Mpeak. For 4 of the children, there was no decrement in speech perception scores immediately following fitting with Speak. Eight of the children showed a small (10% to 20%) decrement in speech perception scores for between 3 and 6 weeks following the changeover to Speak. After 24 weeks' experience with Speak, 11 of the children had shown a steady increase in speech perception scores, with final Speak scores higher than for Mpeak. Only 1 child showed a significant decrement in speech perception with Speak, which did not recover to original Mpeak levels.
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    Speech perception in implanted children: effects of speech processing strategy and residual hearing
    Meskin, T. ; Rance, G. ; Cody, K. ; Sarant, J. ; Larratt, M. ; Latus, K. ; Hollow, R. ; Rehn, C. ; Dowell, R.C. ; Pyman, B. ; Gibson, W.P.R. ; Clark, Graeme M. ; Cowan, Robert S. C. ; Barker, E. J. ; Pegg, P. ; Dettman, S. ; Rennie, M. ; Galvin, K. (Mendoza Editor, 1997)
    The ability of implanted children to adapt to different speech processing strategies has been demonstrated for the Nucleus implant system. Children previously experienced with the Multipeak speech processing strategy. were able to gain significant improvements in consonant, word and sentence perception using the Speak speech processing strategy. suggesting some degree of neural plasticity in neural-auditory coding. Of 192 implanted children with different degrees of preoperative residual hearing, 65% were found to obtain significant scores on open-set speech materials using electrical stimulation alone. Those children with more residual hearing had a greater probability of achieving open-set understanding and at a minimum level, perceived high frequency consonant information which would not have been available through conventional hearing aids.
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    Speech perception in implanted children: effects of preoperative residual hearing and speech processing strategy [Abstract]
    Meskin, T. ; Rance, G. ; Cody, K. ; Sarant, J. ; Larratt, M. ; Latus, K. ; HOLLOW, RODNEY ; Rehn, C. ; Dowell, R.C. ; Pyman, B. ; Gibson, W.P.R. ; Clark, Graeme M. ; Cowan, Robert S. C. ; Barker, E. J. ; Pegg, P. ; Dettman, S. ; Rennie, M. ; Galvin, K. ( 1997)
    Since the first child was implanted with the Nucleus 22-channel cochlear prosthesis in Melbourne in 1985, the number of implanted children world-wide has rapidly expanded. Over this period, more effective paediatric assessment and management procedures have developed, allowing cochlear implants to be offered to children under the age of 2 years. In addition, a succession of improved speech processing strategies have been implemented in the Nucleus implant system, resulting in increased mean speech perception benefits for implanted adults. Research in the Melbourne and Sydney Cochlear Implant Clinics has also demonstrated that young children can adapt to and benefit from improved speech processing strategies such as the Speak strategy. Reported speech perception results for implanted children show that a considerable proportion (60%) of paediatric patients in the Melbourne and Sydney clinics are able to understand some open set speech using electrical stimulation alone. These results, and the upward trend of speech perception benefits to improve over time with advances in speech processing. have raised questions as to whether severely, or severely-to-profoundly deaf children currently using hearing aids would in fact benefit more from a cochlear implant. To investigate the potential effect of the level of preoperative residual hearing on postoperative speech perception. results for all implanted children in the Melbourne and Sydney cochlear implant programs were analysed. Results showed that as 8 group, children with higher levels of preoperative residual hearing were consistently more likely to achieve open-set speech perception benefits. Potential factors in this finding could be higher levels of ganglion cell survival or greater patterning of the auditory pathways using conventional hearing aids prior to implantation. Conversely, children with the least preoperative residual hearing were less predictable, with some children achieving open-set perception, and others showing more limited closed-set benefits to perception. For these children, it is likely that preoperative residual hearing is of less significance than other factors in outcomes.
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    Habilitation issues in the management of children using the cochlear multiple-channel cochlear prosthesis
    Galvin Karyn L. ; Dawson Pam W. ; Hollow Rod. ; Dowell Richard C. ; Pyman B. ; Clark Graeme, M. ; Cowan, Robert S. C. ; Barker, Elizabeth J. ; Dettman, Shani J. ; Blamey, Peter J. ; RANCE, GARY ; Zarant, Julia Z. ( 1993)
    Since 1985, a significant proportion of patients seen In the Melbourne cochlear Implant clinic have been children. The children represent a diverse population, with both congenital and acquired hearing-impairment, a wide-range or hearing levels pre-Implant, and an age range from 2 years to 18 years. The habilitation programme developed for the overall group must be flexible enough to be tailored to the Individual needs of each child, and to adapt to the changing needs or children as they progress. Long-term data shows that children are continuing to show Improvements after 5-7 years of device use, particularly In their perception of open-set words and sentences. Habilitation programs must therefore be geared to the long-term needs of children and their families. Both speech perception and speech production need to be addressed In the specific content of the habilitation program for any Individual child. In addition, for young children, the benefits or Improved speech perception should have an Impact on development of speech and language, and the focus of the programme for this age child will reflect this difference In emphasis. Specific materials and approaches will vary for very young children, school-age and teenage children. In addition, educational selling will have a bearing on the Integration of listening and device use Into the classroom environment.
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    Development of an advanced electrotactile speech processor [Abstract]
    Cowan, Robert S. C. ; Blamey, Peter J. ; Glavin, K. L. ; Sarant, J. Z. ; Millard, R. ; Clark, Graeme M. ( 1992)
    Initial studies with a multiple channel electrotactile speech processor ('Tickle Talker') showed that profoundly hearing-impaired adults and children could achieve significant improvements on speech perception tests through use of tactual-encoded estimates of fundamental frequency, second formant frequency and amplitude envelope. Results showed that the device provided tactual cues which could be used to discriminate speech features such as vowel length and place, and consonant manner and voicing. However, discrimination of initial consonant voicing was not as consistent as for other features. Accurate discrimination of consonant voicing and manner (particularly high frequency information) is critical, since this Information is generally inaudible through hearing aids, and difficult to lipread.