Graeme Clark Collection
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ItemA comparison of Tactaid II+ and Tactaid 7 use by adults with a profound hearing impairment( 1999)Objective: To evaluate and compare use of the Tactaid II+ and the Tactaid 7, in terms of speech perception, by adults with a hearing impairment. Design: Eight adults used one device daily for approximately 10 wk and attended seven training sessions. Performance was measured with tests of phonetic contrast perception, closed-set vowel and consonant identification, word and phoneme recognition in monosyllabic word lists, word recognition in sentences and speechtracking rate. A questionnaire was also administered. The protocol was repeated with the alternative device. Results: With each device, the group discriminated most phonetic contrasts at better-than-chance levels and demonstrated somewhat enhanced visual or auditory-visual perception when measured in terms of vowel identification, monosyllabic word recognition and speechtracking rate. An increase in speechtracking rate was also demonstrated for some individuals. Subjects generally reported little subjective improvement in speech perception and production, but were satisfied with the physical attributes of each device. Five of six subjects preferred the Tactaid 7. Conclusions: The Tactaid II+ and the Tactaid 7 provided suprasegmental and segmental information, enabling the group to discriminate phonetic contrasts and improve their perception of some speech materials. No consistent advantage was found for either device, thought most subjects preferred the Tactaid 7. Alternatives likely to provide a greater benefit to communication should be considered before Tactaid fitting.
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ItemHabilitation issues in the management of children using the cochlear multiple-channel cochlear prosthesis(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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ItemCochlear implants in children, adolescents, and prelinguistically deafened adults: speech perception( 1992)A group of 10 children, adolescents, and prelinguistically deafened adults were implanted with the 22-electrode cochlear implant (Cochlear Ply Ltd) at the University of Melbourne Cochlear Implant Clinic and have used the prosthesis for periods from 12 to 65 months. Postoperative performance on the majority of closed-set speech perception tests was significantly greater than chance, and significantly better than preoperative performance for all of the patients. Five of the children have achieved substantial scores on open-set speech tests using hearing without lipreading. Phoneme scores in monosyllabic words ranged from 30% to 72%; word scores in sentences ranged from 26% to 74%. Four of these 5 children were implanted during preadolescence (aged 5:5 to 10:2 years) and the fifth, who had a progressive loss, was implanted during adolescence (aged 14:8 years). The duration of profound deafness before implantation varied from 2 to 8 years. Improvements were also noted over postoperative data collection times for the younger children. The remaining 5 patients who did not demonstrate open-set recognition were implanted after a longer duration of profound deafness (aged 13:11to 20:1 years). The results are discussed with reference to variables that may affect implant performance, such as age at onset of loss, duration of profound loss, age at implantation, and duration of implantation. They are compared with results for similar groups of children using hearing aids and cochlear implants.
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ItemPerception of multiple electrode stimulus patterns: implications for design of an electrotactile speech processor( 1991)Abstract not available due to copyright.
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ItemThe Tickle Talker: a speech perception aid for profoundly hearing impaired children [Abstract]( 1990)Fifteen prelingually profoundly hearing-impaired children participated in speech perception training and evaluation, to assess potential benefits from use of the Tickle Talker. This device, a multichannel electrotactile speech processor, developed by Cochlear Pty. Ltd. and the University of Melbourne, presents speech as a pattern of electrical sensations felt on the fingers. The eight small electrodes are located over the digital nerve bundles, on both sides of the four fingers of the non-dominant hand. Speech processing hardware is similar to that used in the 22-channel cochlear implant. In the encoding strategy, second formant frequency (F2) is presented as electrode position, speech waveform amplitude as stimulus strength, and fundamental frequency (FO) as rate of stimulation. Each child participated in an ongoing training program involving clinicians, teachers and parents. The evaluation program included measures of sound and speech detection thresholds, and discrimination of speech features, words and open-set sentences. Both individual and mean scores for all the children demonstrate significant improvements in speech perception scores when input from the Tickle Talker is combined with either aided-residual hearing, or aided residual hearing and lipreading. These results are consistent with those previously reported for profoundly hearing-impaired adults using the Tickle Talker, and indicate that children are able to integrate speech information provided through the tactual modality with information from vision or residual hearing.
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ItemPerception of sentences, words, and speech features by profoundly hearing-impaired children using a multichannel electrotactile speech processor( 1990)Abstract not available due to copyright.
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ItemSpeech feature recognition by profoundly hearing impaired children using a multiple-channel electrotactile speech processor and aided residual hearing( 1990)Abstract not available due to copyright.
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ItemSpeech feature recognition with an electrotactile speech processor( 1989)The performance of eight subjects was assessed on a closed-set tactual test battery to evaluate efficiency of the speech feature encoding strategy currently used in the University of Melbourne multichannel electrotactile speech processor. The test battery included twelve subtests of suprasegmental and segmental speech feature contrasts. Results showed that all subjects scored significantly above chance on suprasegmental features such as syllable number, stress and vowel length. In addition, seven of the eight subjects scored significantly above chance for vowel formant frequency discrimination. Scores for manner of articulation contrasts were more variable, with better performance for the higher frequency, longer duration fricatives and affricates. Scores for voicing contrasts suggested that improvements to the tactual coding of this feature could be achieved. The second study examined the contribution of the tactual input to consonant feature identification for subjects using the electrotactile aid in combination with either a low-pass filtered auditory input or different levels of aided residual hearing and lipreading. Results for four normally-hearing subjects showed increased voicing and manner identification scores with the addition of tactual input. Similar results were found for two hearing-impaired subjects, one using the tactual input in combination with lipreading and one using the tactual input in combination with aided residual hearing.
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ItemSpeech perception studies using a multichannel electrotactile speech processor, residual hearing, and lipreading( 1989)Abstract not available due to copyright.
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ItemSpeech perception using combinations of auditory, visual, and tactile information( 1989)Four normally-hearing subjects were trained and tested with all combinations of a highly-degraded auditory input, a visual input via lipreading, and a tactile input using a multichannel electrotactile speech processor. The speech perception of the subjects was assessed with closed sets of vowels, consonants, and multisyllabic words; with open sets of words and sentences, and with speech tracking. When the visual input was added to any combination of other inputs, a significant improvement occurred for every test. Similarly, the auditory input produced a significant improvement for all tests except closed-set vowel recognition. The tactile input produced scores that were significantly greater than chance in isolation, but combined less effectively with the other modalities. The addition of the tactile input did produce significant improvements for vowel recognition in the auditory-tactile condition, for consonant recognition in the auditory-tactile and visual-tactile conditions, and in open-set word recognition in the visual-tactile condition. Information transmission analysis of the features of vowels and consonants indicated that the information from auditory and visual inputs were integrated much more effectively than information from the tactile input. The less effective combination might be due to lack of training with the tactile input, or to more fundamental limitations in the processing of multimodal stimuli.