Graeme Clark Collection

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    A clinical report on speech production of cochlear implant users
    Dawson, P. W. ; Blamey, P. J. ; Dettman, S. J. ; Rowland, L. C. ; Barker, E. J. ; Tobey, E. A. ; Busby, P. A. ; Cowan, R. C. ( 1995)
    Objective: The aim was to assess articulation and speech intelligibility over time in a group of cochlear implant users implanted at 8 yr or over. The hypothesis was that the postoperative speech production performance would be greater than the preoperative performance. Design: A test of intelligibility using sentences and an articulation test measuring non-imitative elicited speech were administered to 11 and 10 subjects, respectively, who were implanted with the 22-electrode cochlear implant. Nine subjects received both tests. Age at implantation ranged from 8 yr to 20 yr and implant use ranged from 1 yr to 4 yr 5 mo. Results: For both the intelligibility and articulation tests roughly half of the subjects showed significant improvements over time and group mean postoperative performance significantly exceeded preoperative performance. Improvements occurred for front, middle, and back consonants; for stops, fricatives, and glides and for voiceless and voiced consonants. Conclusions: Despite being deprived of acoustic speech information for many childhood years, roughly half of the patients assessed showed significant gains in speech intelligibility and articulation postimplantation. The lack of a control group of non-implanted patients means that we cannot separate out the influence of the implant on speech production from other influences such as training and tactile-kinaesthetic feedback.
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    Improved sound processing for cochlear implants
    James, C.J. ; Just, Y. ; Knight, M.R. ; Martin, L.F.A. ; McKay, C.M. ; Plant, K.L. ; Tari, S. ; Vandali, A.E. ; Clark, Graeme M. ; Cowan, R.S.C. ; McDermott, H. J. ; Blamey, P. J. ; Dawson, P. ; Fearn, R. A. ; Grayden, D. B. ; Henshall, K. R. ( 2002)
    Four signal processing schemes currently under development aim to improve the perception of sounds/ especially speech, for children and adults using the Nucleus cochlear implant system. The schemes are (1) fast-acting input-signal compression, (2) Adaptive Dynamic Range Optimisation (ADRO), (3) TESM, a scheme that emphasises transients in signals, and (4) DRSP, a strategy that applies different stimulation rates to selected sets of electrodes.
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    Comparative performance of children using the cochlear 22-channel implant and 8-channel 'Tickle Talker'
    Cowan, Robert S. C. ; Sarant, S. J. ; Dettman, K. L ; Galvin, K. L. ; Blamey, P. J. ; Clark, Graeme M. ( 1992)
    Direct comparison of "Tickle Talker" and Cochlear Implant users is problematic, due to difficulties in matching groups of children for hearing loss, age, duration of deafness, speech perception and language skills, and educational placement. However, two studies were undertaken to compare and contrast potential benefits available from these two devices. In the first study, a number of children from one educational setting were evaluated over a six month period. Half of the children used the multiple channel cochlear implant, while the other half used the multiple channel "Tickle Talker". The number of training sessions, clinicians involved, type of training provided, and overall management philosophy were identical for both devices. Comparison of progress of these two groups of children demonstrates that both devices are effective in improving' communication. However, differences were found with the tactile device being more limited in information provided and speech perception benefits. In the second study, two children who have used both devices were evaluated. These two children initially used the ''Tickle Talker" for periods up to two years, and subsequently had a multiple-channel cochlear implant. Similar habilitation was provided to these children with both devices, and measures of speech perception were taken at similar time periods. Results for one of the children, a prelinguistically deafened adolescent, already show similar benefits in terms of supplementation of lipreading for both devices. However, this patient has also shown some open-set word and sentence perception using the implant-alone. To date, this level of performance has not been achieved with the ''Tickle Talker". The results of these studies suggest a role for a multiple channel tactile device in a cochlear implant clinic as a training device for evaluating the ability of adults or children to integrate speech information presented through different sensory modalities. This could facilitate pre-implant evaluation of the potential for children to benefit from added speech information, which is often difficult to evaluate in congenitally deaf children.