Graeme Clark Collection

Permanent URI for this collection

Search Results

Now showing 1 - 10 of 42
  • Item
    Thumbnail Image
    The effects of electrode position and stimulus period on the hearing sensations in a multiple-channel cochlear implant patient [Abstract]
    Tong, Y. C. ; Blamey, P. J. ; Dowell, R. C. ; Clark, Graeme M. ( 1981)
    Abstract not available due to copyright.
  • Item
    Thumbnail Image
    Perceptual dissimilarity and discrimination studies using two-electrode stimulation with a multiple-channel cochlear implant patient [Abstract]
    Dowell, R. C. ; Tong, Y. C. ; Blamey, P. J. ; Clark, Graeme M. ( 1981)
    Abstract not available due to copyright.
  • Item
    Thumbnail Image
    Speech feature encoding through an electrotactile speech processor [Abstract]
    Cowan, Robert S. C. ; Blamey, Peter J. ; Alcantara, Joseph I. ; Whitford, Lesley A. ; Clark, Graeme M. ( 1989)
    Abstract not available due to copyright.
  • Item
    Thumbnail Image
    Results in children using the 22 electrode cochlear implant [Abstract]
    Dawson, Pam W. ; Blamey, Peter J. ; Clark, Graeme M. ; Busby, P. A. ; Rowland, L.C. ; Dettman, S. J. ; Brown, A. M. ; Dowell, Richard C. ; Rickards, Field W. ; Alcantara, Joseph I. ( 1989)
    Abstract not available due to copyright.
  • Item
    Thumbnail Image
    Speech feature recognition with an electrotactile speech processor
    Cowan, R. S. C. ; Blamey, P. J. ; Alcantara, J. I. ; Clark, Graeme M. ; Whitford, L. A. ( 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.
  • Item
    Thumbnail Image
    Speech perception studies using a multichannel electrotactile speech processor, residual hearing, and lipreading
    Cowan, Robert S. C. ; Alcantara, Joseph I. ; Whitford, Lesley A. ; Blamey, Peter J. ; Clark, Graeme M. ( 1989)
    Abstract not available due to copyright.
  • Item
    Thumbnail Image
    Speech perception using combinations of auditory, visual, and tactile information
    Blamey, Peter J. ; Cowan, Robert S. C. ; Alcantara, Joseph I. ; Whitford, Lesley A. ; Clark, Graeme M. ( 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.
  • Item
    Thumbnail Image
    Speech feature recognition by profoundly deaf children using the University of Melbourne multichannel electrotactile aid [Abstract]
    Alcantara, Joseph I. ; Whitford, Lesley A. ; Blamey, Peter J. ; Cowan, Robert S. C. ; Clark, Graeme M. ( 1989)
    Abstract not available due to copyright.
  • Item
    Thumbnail Image
    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.
  • Item
    Thumbnail Image
    Preliminary evaluation of a wearable multichannel electrotactile speech processor [Abstract]
    Cowan, R. S. C. ; Blamey, P. J. ; Alcantara, J. I. ; Whitford, L. W. ; Clark, Graeme M. ( 1988)
    Speech discrimination testing, using both open-and closed-set materials was carried out with four severely-to-profoundly hearing impaired adults. and seven normally hearing subjects, to assess performance of a wearable eight-channel electrotactile aid (Tickle Talker). The device consisted of a handset composed of nine electrodes, a stimulator-unit, and a speech processor and input microphone. Eight small electrodes were located over the digital nerve bundles on each side of the four fingers of one hand, and a larger common electrode was placed on the wrist. Subjects perceived eight separate channels of information, each corresponding to a stimulus on one side of one finger. The speech processor provided estimates of second formant frequency, fundamental frequency and amplitude of the speech waveform. These features were coded as electrode position, pulse rate and pulse width respectively. This processing strategy (FOF2AO) is similar to that used in an earlier model of the Cochlear Pty. Ltd. cochlear implant.