Graeme Clark Collection

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    A modification of play audiometry to assess speech discrimination ability in severe-profoundly deaf 2- to 4-year-old children
    Dawson, P. W. ; Nott, P. E. ; Clark, Graeme M. ; Cowan, Robert S. C. ( 1998)
    Objective: The aim was to develop an assessment procedure that was independent of language and speech production ability, to test speech feature discrimination severe-profoundly deaf children 2 to 4 yr of age. Design: The procedure being trialled was adapted from existing procedures. The child was required to respond with a game-like motor response to a “change” in a speech stimulus that was being presented repeatedly through a speaker. The change occurred at randomly determined times, and false alarm responses were measured during the waiting periods (while the child waited for the change). Two- to four-yr-old normally hearing children and hearing-impaired children using hearing aids and a group of 4-yr-old hearing-impaired children using cochlear implants were assessed on the task. Results: More than 82% of the 3- and 4-yr-old normally hearing and hearing-impaired children were able to complete the testing for the eight speech sound contrasts within three 20 minute sessions. Fifty percent of the 2-yr-old normally hearing and hearing-impaired children were able to condition and complete the task. All of the normally hearing children who completed the task successfully discriminated all speech sound contrasts. The performance of the hearing-impaired children using hearing aids was influenced by the degree of hearing loss and the type of speech contrast being tested. Similarly, the average performance of the children using cochlear implants was better for easier contrasts such as /ba/bi/ with contrasting vowel formant cues. Conclusions: This procedure has potential for use as a reliable clinical and research tool for assessing the development of auditory discrimination ability in 2- to 4-yr-old severe-profoundly deaf children.
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    Habilitation issues in the management of children using the cochlear multiple-channel cochlear prosthesis
    Cowan, Robert S. C. ; Barker, Elizabeth J. ; Dettman, Shani J. ; Blamey, Peter J. ; RANCE, GARY ; Sarant, Julia Z. ; Galvin, Karyn L. ; Dawson, Pam W. ; Hollow, Rod ; Dowell, Richard C. ; PYMAN, BRIAN ; Clark, Graeme M. (Wien, 1994)
    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-impairments, a wide-range of 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 of 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 of 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 setting will have a bearing on the integration of listening and device use into the classroom environment.
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    The effects of auditory feedback from the nucleus cochlear implant on the vowel formant frequencies produced by children and adults
    Richardson, Louise M. ; Busby, Peter A. ; Blamey, Peter J. ; Dowell, Richard C. ; Clark, Graeme M. ( 1993)
    Cochlear implants provide an auditory signal with which profoundly deaf users may monitor their own speech production. The vowel production of two adults and three children who used the Nucleus multiple-electrode cochlear implant was examined to assess the effect of altered auditory feedback. Productions of words were recorded under conditions where the talkers received auditory feedback (speech processor turned on) and where no auditory feedback was provided (speech processor turned off). Data were collected over 3 days at weekly intervals. First and second formant frequencies were measured and the data were analysed to assess significant differences between auditory feedback conditions, vowel context, and data collection points. Overall, the results varied across talkers, across the data collection days, and depended on the consonant environment of the vowel. However, two effects of auditory feedback were noted. First, there was a generalized shift in first formant frequencies between the processor on and processor off conditions across three of the five subjects, but the shift differed in direction for each subject. Second, for three of the five talkers, the two front vowels /ε/ and /I/ were more neutralised in the absence of auditory feedback. However, this effect was less pronounced than that noted by previous studies.
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    Results of speech perception and speech production training for three prelingually deaf parents using a multiple-electrode cochlear implant
    Busby, P. A. ; Roberts, S. A. ; Tong, Y. C. ; Clark, Graeme M. ( 1991)
    Five studies were conducted to measure changes in the perception and production of selected speech targets, with training, in three prelingually deaf patients. The two adults and one adolescent were implanted with the Cochlear (Nucleus) multiple-electrode prosthesis. The studies were perception and production of nasal consonants; perception of syllable-final consonants; perception and production of alveolar consonants; auditory-visual perception of alveolar consonants; and perception and production of vowels. Perceptual data were collected in the audition (implant)-alone condition, except for the auditory visual perception of alveolar consonants where the audition-alone, vision-alone, and auditory-visual conditions were used. Speech perception data in the audition-alone condition were also collected from four postlingually deaf adult implant patients, without training, to indicate differences between the two classes of patients. The three prelingually deaf patients generally showed some improvements in speech production. In perception, improvements were recorded only for individual patients in some studies. The performance of the adolescent was better than that of the two adults in all cases. The perceptual performance of the postlingually deaf patients was superior to that of the prelingually deaf patients in all cases.
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    Perception of sentences, words, and speech features by profoundly hearing-impaired children using a multichannel electrotactile speech processor
    Cowan, Robert S. C. ; Blamey, Peter J. ; Galvin, Karyn L. ; Sarant, Julia Z. ; Alcantara, Joseph I. ; Clark, Graeme M. ( 1990)
    Abstract not available due to copyright.
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    Results for two children using a multiple-electrode intracochlear implant
    Busby, P. A. ; Tong, Yit C. ; Roberts, S. A. ; Altidis, P. M. ; Dettman, S. J. ; Blamey, Peter J. ; Clark, Graeme M. ; Watson, R. K. ; Rickards, Field W. ( 1989)
    Abstract not available due to copyright.
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    Speech perception & indirect benefits for severely hearing impaired children using cochlear implants [Abstract]
    Cowan, Robert S. C. ; Dowell, Richard C. ; Nott, P. ; Rennie, Maree ; Pyman, B. ; Clark, Graeme M. ( 1998)
    The benefits to speech perception, speech production, communication, and quality of life were investigated for severely hearing impaired children using cochlear implants and hearing aids. For the youngest children, assessments of psychological status, and use of a battery of cognitive and language tests were important factors in determining performance benefits prior to the child developing speech. For older children, the effects of increased one-to-one oral habilitation, and systematic encouragement of parental involvement were also investigated. Results suggested that parental support for consistent device use was an important factor in producing outcomes. Children with residual hearing were more likely to achieve open-set perception. Each child was also assessed for changes in quality of life, through use of a standardized health utility instrument. Results from the group were collated, and teamed with a costing assessment for the procedure, which allowed a complete cost-utility analysis to be completed. Results suggested that indirect benefits, such as the effects on speech production, usual activities, lower concentration, and less distress were ranked as more important than changes to hearing in a number of the children. Costs per QALY were consistent with those reported in the literature, and suggested that the cochlear implant is highly cost-effective as a medical technology.
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    Speech perception, production and language results in a group of children using the 22-electrode cochlear implant
    Busby, P. A. ; Brown, A. M. ; DOWELL, RICHARD ; Rickards, Field W. ; Dawson, Pam W. ; Blamey, Peter J. ; Rowland, L.C. ; Dettman, Shani J. ; Altidis, P. M. ; Clark, Graeme M. ( 1989)
    Paper presented at the 118th Meeting of the Acoustical Society of America
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    Results for the Nucleus multiple-electrode cochlear implant in two children [Abstract]
    Tong, Y. C. ; Blamey, P. J. ; Dowell, R. C. ; Nienhuys, T. G. ; Musgrave, G. N. ; Busby, P. A. ; Roberts, S. A. ; Rickards, F. W. ; Dettman, S. J. ; Altidis, P. M. ; Clark, Graeme M. ( 1988)
    Two males, 9 years 10 months (CHILD 1) and 5 years 5 months (CHILD 2) at time of surgery, were implanted with the Nucleus multiple-electrode cochlear implant. Both patients were deafened as a result of meningitis in their third year. Assessments of speech perception, speech production and language skills were undertaken at regular intervals, pre and post operatively. For both patients in the audition alone condition, some speech perception post operative scores were significantly higher than pre operative scores and progressive improvements in scores over successive post operative data collection times were seen. Significant differences between the visual alone and auditory-visual condition scores were also observed for CHILD 1 post operatively. Speech production post operative scores were significantly higher than pre operative scores for both patients. The receptive vocabulary scores for both patients improved at a higher rate than that of age-matched normal children. The acquisition of expressive and receptive language skills for CHILD 2 was at a higher rate than that of age-matched children. Differences in the results between the two patients were seen, and this may be related to age and duration of deafness.