Graeme Clark Collection

Permanent URI for this collection

Search Results

Now showing 1 - 10 of 17
  • Item
    Thumbnail Image
    Cognitive processing in children using cochlear implants: the relationship between visual memory, attention, and executive functions and developing language skills
    Surowiecki, Vanessa N. ; SARANT, JULIA ; MARUFF, PAUL ; Blamey, Peter J. ; Busby, Peter A. ; Clark, Graeme M. ( 2002)
    We performed this study to determine whether children using a cochlear implant performed differently from age- and gender-matched hearing aid users on 8 neuropsychological measures of visual memory, attention, and executive functioning. The study also examined whether differences in cognitive skills could account for some of the observed variance in speech perception, vocabulary, and language abilities of hearing-impaired children. In contrast to previous studies, our results revealed no significant cognitive differences between children who use a cochlear implant and children who use hearing aids. Partial correlation analysis indicated that the children’s visual memory skills, i.e., their recognition memory, delayed recall, and paired associative learning memory skills, correlated significantly with their language skills. When examined at a significance level of .01, attention and executive functioning skills did not relate to the children’s developing speech perception, vocabulary, or language skills. The results suggested that differences in visual memory skills may account for some of the variance seen in the language abilities of children using implants and children using hearing aids.
  • Item
    Thumbnail Image
    Variation in speech perception scores among children with cochlear implants
    Sarant, JZ ; Blamey, PJ ; Dowell, RC ; Clark, GM ; Gibson, WPR (LIPPINCOTT WILLIAMS & WILKINS, 2001-02)
    OBJECTIVE: The objective of this study was to identify common factors affecting speech perception scores in children with cochlear implants. DESIGN: Speech perception data for 167 implanted children were collected at two cochlear implant centres in Melbourne and Sydney. The data comprised audition-alone scores on open-set word and sentence tests. Children were selected on the basis that they had a Nucleus 22-electrode cochlear implant. The average age of the children was 5 yr. Information was also collected about 12 factors that may have influenced speech perception scores for each child. Analysis of covariance was used to identify factors that significantly affected speech perception scores. Pearson pairwise correlation coefficients were also calculated for all factors analyzed. RESULTS: The analyses in this study identified factors that accounted for 51%, 34%, and 45% of the variance in phoneme, word and sentence perception scores. Scores decreased by 1.4 to 2.4% per year of profound deafness prior to implantation. Children who normally use oral communication scored significantly higher than children normally using sign or simultaneous oral and sign communication. Children implanted in Sydney scored higher on average than children implanted in Melbourne. CONCLUSIONS: The results show that a significant part of the variation in speech perception scores is systematically related to audiological and environmental factors for each child. The reasons for significant differences between children using different communication modes or from different clinics were not identified.
  • Item
    Thumbnail Image
    The effect of language knowledge on speech perception: what are we really assessing?
    Sarant, Julia Z. ; Blamey, Peter J. ; Cowan, Robert S. ; Clark, Graeme M. ( 1997)
    Objective: The authors examined whether open-set speech perception scores are limited by knowledge of vocabulary and syntax and further considered whether remediation of vocabulary and syntax will increase open-set speech perception scores. Study Design: This was a repeated-measures study design in the setting of a primary (elementary) school for the hearing impaired. Patients: The study population was composed of three hearing-impaired children using Nucleus 22-channel cochlear implant. Intervention: Intervention used was language remediation sessions. Main Outcome Measures: The main outcome measures were assessment of auditory-alone speech perception benefit using open-set words and sentences and assessment of syntactic knowledge using the Test of Syntactic Ability. Outcome measures were applied before and after remediation. Results: Child 1 and child 2 showed a significant postremediation improvement in their overall scores on the Test of Syntactic Ability and in their ability to perceive words learned during remediation. Child I and child 2 also showed a significant improvement in their scores on a modified Bamford-Kowal-Bench open-set sentence test, which specifically targeted grammatical constructs trained in remediation sessions. Conclusions: Remediation of language knowledge deficits significantly improved open-set speech perception for two children, suggesting a need to include language remediation in cochlear implant habilitation programs.
  • Item
    Thumbnail Image
    Design fundamentals for electrotactile devices: the Tickle Talker case study
    Cowan, Robert S. C. ; Galvin, Karyn L. ; Blamey, Peter J. ; Sarant, Julia Z. (Whurr, 1995)
    Since the work of Gault in the 1920s, the literature has chronicled the development of numerous tactile devices for use by the hearing impaired in improving communication. Devices have been developed to target improvements in both speech perception and speech production. In each development, the inventors have attempted to encode speech information through stimulation of the intact kinaesthetic system of the individual, as a supplement or replacement for speech input available from the damaged auditory pathway.
  • Item
    Thumbnail Image
    Within-subject comparison of speech perception benefits with a multiple-channel cochlear implant and tactile device
    Sarant, J. Z. ; Cowan, R. S. C. ; Blamey, P. J. ; Galvin, K. L. ; Clark, Graeme M. ( 1995)
    In order to adequately advise prospective cochlear implant patients and their families, a clinician must have a good knowledge of the potential for particular individuals to benefit from cochlear implants and other alternatives.
  • Item
    Thumbnail Image
    Speech self-monitoring by children using an electrotactile speech processor
    Galvin, K. L. ; Cowan, R. S. C. ; Sarant, J. Z. ; Tobey, E. A. ; Blamey, P. J. ; Clark, Graeme M. ( 1995)
    For the profoundly and severely-to-profoundly hearing impaired child, lipreading and hearing aids are not always sufficient to develop adequate speech perception and production skills. Tactile devices have been investigated as a source of supplementary speech information, with most research focusing on speech perception benefits. However, speech production difficulties are also a major issue for these children, and research into tactile devices should include investigation of the option to use them as speech production aids. This paper will present the results from an initial examination of the suitability of one tactile device for speech production monitoring.
  • Item
    Thumbnail Image
    Improved electrotactile speech processor: Tickle Talker
    Cowan, R. S. C. ; Galvin, K. L. ; Sarant, J. Z. ; Millard, R. ; Blamey, P. J. ; Clark, Graeme M. ( 1995)
    The Tickle Talker, an eight-channel electrotactile speech processor, has been developed from continuing research at the University of Melbourne. 'The development of the device has focused on production of reliable speech-processing hardware, design of cosmetically and ergonometrically acceptable electrode transducers, implementation of acute and chronic biomedical studies demonstrating device safety, design and testing of alternative speech-encoding strategies to provide benefit to speech perception and production, and design and testing of appropriate training methods for optimizing benefits. The Tickle Talker has been shown to provide benefits in supplementing lipreading or aided residual hearing for hearing-impaired adults and children. Improvements in speech processing have resulted in an increase in benefits to speech perception, and open the way for more flexible approaches to encoding speech input. Continuing development of the electrode circuitry has now produced a device that is robust and has an extended battery life. Safety studies have clearly demonstrated that there are no long-term contraindications to device use. The results suggest that the device has a role to play in rehabilitation programs for severely and profoundly hearing-impaired adults and children.
  • Item
    Thumbnail Image
    Issues in long-term management of children with cochlear implants and tactile devices [Abstract]
    COWAN, ROBERT ; DOWELL, RICHARD ; Barker, Elizabeth ; GALVIN, KARYN ; DETTMAN, SHANI ; SARANT, JULIA ; RANCE, GARY ; Hollow, Rod ; BLAMEY, PETER ; Clark, Graeme M. ( 1994)
    For many children with severe and profound hearing losses, conventional hearing aids are unable to provide sufficient amplification to ensure good oral communication and/or in the case of very young children, development of speech and language. Traditionally a number of these children have opted for the use of sign language alone or in Total Communication approaches as a primary means of communication. The advent of multiple channel cochlear implants for children and the continuing development of multiple channel speech processing tactile devices provide auditory approaches to resolving communication difficulties for these children. The successful use of such devices depends on a number of factors including the information provided through the aid; the ease of use, convenience and reliability of the aid; the individual communication needs of the child; and the habilitation and management program used with the device. Long-term data has shown that children continue to show increased speech perception benefits from improvements in speech processing and from further experience with these devices. Habilitation and management programs must therefore be geared to meet the changing needs of children as they progress and of families as children mature and face new challenges. Habilitation must address specific individual needs in speech perception and in speech production. For very young children, benefits of improved speech perception should have an impact on the development of speech and language, and habilitation and management must emphasise the need for language growth.
  • Item
    Thumbnail Image
    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.
  • Item
    Thumbnail Image
    Cochlear implants for congenitally deaf adolescents: is open-set speech perception a realistic expectation?
    Sarant, J. Z. ; Cowan, R. S. C. ; Blamey, P. J. ; Galvin, K. L. ; Clark, Graeme M. ( 1994)
    The prognosis for benefit from use of cochlear implants in congenitally deaf adolescents, who have a long duration of profound deafness prior to implantation, has typically been low. Speech perception results for two congenitally deaf patients implanted as adolescents at the University of Melbourne/Royal Victorian Eye and Ear Hospital Clinic show that, after 12 months of experience, both patients had significant open-set speech discrimination scores without lipreading. These results suggest that although benefits may in general be low for congenitally deaf adolescents, individuals may attain significant benefits to speech perception after a short period of experience. Prospective patients from this group should therefore be considered on an individual basis with regard to prognosis for benefit from cochlear implantation.