Graeme Clark Collection

Permanent URI for this collection

Search Results

Now showing 1 - 6 of 6
  • Item
    Thumbnail Image
    Electrode discrimination and speech perception in young children using cochlear implants
    Dawson, P. W. ; McKay, C. M. ; Busby, P. A. ; Grayden, D. B. ; Clark, Graeme M. ( 2000)
    Objective: The aim was to determine the efficacy of a child-appropriate procedure to assess electrode discrimination ability in young children using cochlear implants and to investigate the relationship of electrode discrimination ability and speech perception performance in children implanted at a young age. Design: An adaptation of the play audiometry procedure was used to assess electrode discrimination in seventeen 4- to 10-yr-old children. The children were required to respond with a game-like motor response when a repeating stimulation on a reference electrode “changed” to a different electrode. They were also assessed on a speech feature discrimination test, a closed-set word recognition test and a nonverbal intelligence task. Results: Sixty-five percent of subjects demonstrated ability to discriminate adjacent electrodes in mid and apical regions of the cochlea, whilst the remaining subjects needed electrode separations of between two and nine electrodes for successful discrimination. In a forward stepwise regression analysis electrode discrimination ability was found to be the strongest factor in accounting for variance in the speech perception scores. Subject variables such as duration of deafness, nonverbal intelligence and implant experience did not significantly account for further variance in the speech perception scores for this group of children. Conclusions: Electrode discrimination ability was the strongest factor in predicting performance on speech perception measures in a group of children using cochlear implants.
  • Item
    Thumbnail Image
    Physiological and histopathological effects of chronic monopolar high rate stimulation on the auditory nerve
    TYKOCINSKI, MICHAEL ; Linahan, N. ; Shepherd, R. K. ; Clark, Graeme M. ( 2000)
    Speech processing strategies based on high rate electrical stimulation have been associated with improvements in speech perception among cochlear implant users. The present study was designed to evaluate the electrophysiological and histopathological effects of long-term intracochlear monopolar stimulation at the maximum stimulus rate of the current Nucleus Cochlear implant system (14493 pulses/s) as part of our ongoing investigations of safety issues associated with cochlear implants
  • Item
    Thumbnail Image
    Pre-operative hearing assessment in young cochlear implant candidates
    RANCE, GARY ; Dowell, Richard C. ; Rickards, Field W. ; Clark, Graeme M. ( 2000)
    Early implantation of congenitally deaf candidates is now a goal of most cochlear implant clinics. This objective can only be achieved through the use of audiological tests that are able to identify and quantify hearing loss in infancy. Behavioural conditioning techniques provide the most accurate indication of hearing acuity in older subjects, but these procedures are unreliable in young (6 months) or developmentally delayed children. This paper investigates the degree of accuracy with which two electrophysiological test techniques (click-ABR & steady-state evoked potential [SSEPD can be used to assess auditory function in infants with significant hearing loss. ABR and SSEP findings from 108 children were compared with hearing levels obtained behaviourally.
  • Item
    Thumbnail Image
    What factors contribute to successful outcomes for children using cochlear implants
    Cowan, Robert C. ; Clark, Graeme M. ; Dowell, Richard C. ; Dettman, Shani J ; Barker, Elizabeth ; Latus, Katie ; Hollow, Rod ; Blamey, Peter J. ( 2000)
    Long term speech perception data has been collected for 100 children using the Nucleus multichannel cochlear prosthesis in Melbourne. Scores on a number of different assessments are available at approximately six month intervals following implantation for these children. The group represents an unselected sample of cochlear implant users, as all children were included if they had sufficient developmental skills to perform formal speech perception tests. Information was also collected on each child regarding type of hearing loss, age of onset of profound hearing loss, duration of profound hearing loss, age at implantation, pre and post-implant communication mode, developmental delay, speech processing strategy and length of experience with implant use.
  • Item
    Thumbnail Image
    Application of the cochlear implant to profoundly hearing impaired adolescents: re-visiting the inclusion criterion for older children
    DETTMAN, SHANI ; Latus, Katie ; Cosson, Liz ; Dowell, Richard C. ; Clark, Graeme M. ( 2000)
    Objective: The purpose of this study is to examine the range of outcomes for older children receiving the multi-channel cochlear implant. Recent improvements in the speech perception performance for profoundly hearing impaired children and adults have lead to expanded selection criterion for cochlear implant inclusion. That is, the efficacy of cochlear implants for adults with acquired hearing loss is well documented. In addition, the application of the cochlear implant to young children has lead to improvements in open set speech perception, speech production and language acquisition. In contrast, congenitally deaf and prelingually deafened children who are implanted after the age of 8 years have performed poorer than children implanted at a younger age on speech perception, speech production and psychophysical performance measures.
  • Item
    Thumbnail Image
    Speech perception in noise with cochlear implant and hearing aid for implanted adolescents
    DETTMAN, SHANI ; Latus, Katie ; Cosson, Liz ; Dowell, Richard C. ; Clark, Graeme M. ( 2000)
    Objective. To describe the open set speech perception performance for 8 congenitally deaf adolescents who use a multichannel cochlear implant and behind-the ear hearing aid as their 'everyday listening' condition. Expanded indication for cochlear implant inclusion has lead to the implantation of a number of persons with severe to profound hearing loss. It has been suggested that persons who have some residual bearing are good candidates for the cochlear implant due to: the presence of more ganglion cells, prior auditory experience, pre-patterning of the auditory cortex or other factors, as yet unknown, such as language experience.