Graeme Clark Collection

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    A multiple-channel cochlear implant: an evaluation using nonsense syllables
    Clark, Graeme M. ; Tong, Yit Chow ; Martin, Lois F. ; Busby, Peter A. ; Dowell, Richard C. ; Seligman, Peter M. ; Patrick, James F. ( 1981)
    A study using nonsense syllables has shown that a multiple-channel cochlear implant with speech processor is effective in providing information about, voicing and manner and to a lesser extent place distinctions. These distinctions supplement lipreading cues. Furthermore, the average percentage improvements in overall identification scores for multiple-channel electrical stimulation and lipreading compared to lipreading alone were 71% for a laboratory-based speech processor and 122 % for a wearable unit.
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    Acoustic parameters measured by a formant-estimating speech processor for a multiple-channel cochlear implant
    Blamey, P. J. ; Dowell, R. C. ; Clark, Graeme M. ; Seligman, P. M. ( 1987)
    Abstract not available due to copyright.
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    Vowel and consonant recognition of cochlear implant patients using formant-estimating speech processors
    Blamey, P. J. ; Dowell, R. C. ; Brown, A. M. ; Clark, Graeme M. ; Seligman, P. M. ( 1987)
    Abstract not available due to copyright.
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    A formant-estimating speech processor for cochlear implant patients
    Blamey, P. J. ; Dowell, R. C. ; Brown, A. M. ; Clark, Graeme M. ; Seligman, P. M. ( 1987)
    A simple formant-estimating speech processor has been developed to make use of the “hearing” produced by electrical stimulation of the auditory nerve with a multiple-channel cochlear implant. Thirteen implant patients were trained and evaluated with a processor that presented the second formant frequency, fundamental frequency, and amplitude envelope of the speech (F0F2). Nine patients were trained and evaluated with a processor that presented the first and second formant frequencies, fundamental frequency, and first and second formant amplitudes (F0F1F2). The most common use of the speech processor was in conjunction with lipreading, so the patients were trained in lipreading plus hearing, as well as hearing alone. The F0F1F2 group performed significantly better in discrimination tasks and word and sentence recognition through hearing alone. The F0F1F2 group also showed a significantly greater improvement when hearing and lipreading was compared with lipreading alone in a speech tracking task. A study of spondee recognition in noise with hearing alone indicated that the added first formant information produced an improvement that was equivalent to a 5 dB increase in the signal-to-noise ratio.
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    Clinical trial of a multi-channel cochlear prosthesis: results on 10 postlingually deaf patients
    Clark, Graeme M. ; Dowell, R. C. ; Pyman, B. C. ; Brown, A. M. ; Webb, R. L. ; Tong, Y. C. ; Bailey, Q. ; Seligman, P. M. ( 1984)
    The clinical trial of a multi-channel cochlear prosthesis has been carried out on 10 profoundly-totally deaf adult patients. Speech perception tests have shown that all the patients received significant benefit from the device. They obtained improvements in understanding running speech from 47% to 550% when using the device in conjunction with lipreading compared to lipreading alone. With an open-set CID sentence test, three patients obtained scores showing an ability to understand speech without the need to lipread, and a further three patients had scores indicating they could also receive useful information without lipreading. In two patients, very limited open-set scores for electrical stimulation alone were obtained. This was most probably due to the fact that only a few channels of stimulation were possible due to cochlear disease and they were therefore receiving information more like a single-channel device. The prosthesis has also been found to provide considerable help in hearing and recognizing everyday sounds.
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    A 12-consonant confusion study on a multiple-channel cochlear implant patient
    Dowell, R. C. ; Martin, L. F. A. ; Tong, Y. C. ; Clark, Graeme M. ; Seligman, P. M. ; Patrick, J. F. ( 1982)
    A consonant confusion study was undertaken on a multiple-channel cochlear implant patient using a wearable speech processing device. This patient suffered from total bilateral deafness acquired postlingually. The consonants /b/, /p/, /m/, /v/, /f/, /d/, /t/,/n/, /z/, /s/, /g/, /k/ were presented in VCV context with the vowel /a/ as in father by a male and female speaker under three conditions: lipreading alone; electrical stimulation alone using the wearable speech processor and multiple-channel cochlear implant; lipreading in conjunction with electrical stimulation. No significant difference was detected between the results for the male and female speakers. The percentage correct scores for the pooled results of both speakers were lipreading alone - 30%; electrical stimulation alone - 48%; lipreading with electrical simulation - 70%. Performance was significantly better for lipreading with electrical stimulation than for lipreading alone and for electrical stimulation alone than for lipreading alone. An information transmission analysis demonstrated the effective integration of visual and auditory information for lipreading with electrical stimulation. There was a significant improvement in performance for the electrical stimulation alone condition over the 2 months of the study in contrast to no such improvement for lipreading alone.