Graeme Clark Collection

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    A multiple-channel cochlear implant: evaluation using speech tracking
    Martin, Lois F. A. ; Tong, Yit Chow ; Clark, Graeme M. ( 1981)
    Two totally deaf patients who had received multiple-channel cochlear implants were tested using a speech "tracking" procedure in which they had to repeat verbatim passages of connected discourse. Their performance was assessed by calculating the tracking rate (words per minute) each session. Testing was carried out under two conditions - lipreading along and lipreading in conjunction with a multiple-channel cochlear implant and laboratory speech processor. Lipreading with the cochlear implant increased the tracking rates by a factor of four for one patient and by a factor of two for the other when compared with lipreading alone.
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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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    A multiple-channel cochlear implant: an evaluation using an open-set word test
    Clark, Graeme M. ; Tong, Y. C. ; Martin, L. F. ; Busby, P. A. ( 1981)
    Multiple-channel electrical stimulation of the hearing nerve in conjunction with speech reading has helped two post-lingually deaf patients with total hearing losses understand running speech in every day situations. This has been confirmed using open-set phonetically balanced word tests, where the patients achieved 60% and 40% scores with isolated-words and 80% and 73% for phonemes-in-isolated words. The tests also showed that the cochlear implant improved word recognition by a factor of four in one patient and two in another compared with speechreading alone. The speech processor used extracted the voicing frequency and energy and the frequency and energy of the dominant spectral peak in the mid-frequency range. The parameters for voicing determined the rate of stimulation for all electrodes, and the parameters for the dominant spectral peak in the midfrequency range determined the site of electrode stimulation and current level.
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    Clinical results for postlingually deaf patients implanted with multichannel cochlear prostheses
    Brown, A. M. ; Dowell, R. C. ; Clark, Graeme M. ( 1987)
    Clinical results for 24 patients using the Nucleus 22-channel cochlear prosthesis have shown the device to be successful in presenting amplitude, fundamental frequency, and second formant information to patients with acquired hearing loss. For all patients, this has meant a significant improvement in their communication ability when using lipreading and some ability to understand unknown speech without lipreading or contextual cues. Approximately 40% of patients are able to understand running speech in a limited fashion without lipreading, and this ability has been evaluated using the speech-tracking technique for a number of patients. Many patients are able to have limited conversations on the telephone without using a special code. Although the prosthesis has been designed with the presentation of speech signals in mind, recognition and discrimination of environmental sounds has also been very encouraging with patients scoring 70% to 80% correct for closed set environmental sound testing. Follow-up testing has indicated that the ability to understand open set speech without lipreading continues to improve up to at least 12 months postoperatively. Open set sentence test results improved from an average of 20% at 3 months to 40% at 12 months.
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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.