Graeme Clark Collection
Permanent URI for this collection
Search Results
1 - 7 of 7
-
ItemThe clinical assessment of cochlear implant patients(Cambridge University Press, 1977)This paper is a discussion of the clinical assessment routine adopted following experience gained over the last three years from evaluating 27 patients with severe sensori-neural deafness to determine whether they are suitable for the cochlear implantation of a multiple-electrode receiving and stimulating device developed jointly in the Departments of Otolaryngology and Electrical Engineering at the University of Melbourne.
-
ItemThe effects of muscle relaxants on auditory evoked potentials in humans(Cambridge University Press, 1973)In studies on auditory sensory information processing it is frequently assumed that the average evoked potentials from the scalp are produced by neural generators in the cortex. This may not be the case as there is evidence to suggest that at least one component of the auditory evoked response may be myogenic (Bickford et al., 1964). Therefore, the present study was undertaken to help determine the extent to which auditory evoked responses are myogenic or neurogenic.
-
ItemAuditory evoked responses to frequency and amplitude modulated sound( 1973)Auditory evoked responses to pure tone bursts have been described in a number of studies and have been characterized by the P1, N1 and P2 components. The presence of later components, namely N2, P3 and the Contingent Negative Variation, depends largely on the cerebral processing of the stimulus. These evoked responses have been recorded using tone bursts. However, neurophysiological studies have shown that the cortex codes complex sounds. Therefore, we performed a set of acute experiments on the cat, using frequency and amplitude modulated sounds. This was reported in a previous study (Richards and Clark, 1972) which showed that similar onset and later waves could be recorded from the cortex of the cat. In some areas of the cortex the later waves were in synchrony with the modulation envelope.
-
ItemCortical evoked response audiometry( 1973)Standard audiometry requires the patient to co-operate and to respond to an auditory stimulus. Thus reliance is placed on the patient's own judgment. There are a few clinical situations where the patient's co-operation cannot be gained or his judgment relied upon. Thus methods of audiometric testing have been derived which rely on observer judgment only. One of these objective methods of audiometry which is being investigated is Evoked Cortical Response Audiometry.
-
ItemThe diagnosis and management of communication disorders in children( 1973)Communication disorders are common and may occur if the child has loss of hearing, is mentally retarded, has autism or suffers from higher level language disorders like aphasia and dyslexia.
-
ItemThe effects of muscle relaxants on the auditory cortical evoked potentials in humans( 1972)There are a number of studies on sensory information processing based on an analysis of cortical evoked potentials. Few studies however, provide direct evidence that the cortical evoked potentials are produced by neural generators in the brain. In fact, some research work has shown that most of the cortical evoked activity may be muscular in origin. (Bickford et al, 1964; Prichard et al, 1965). Consequently the present study was necessary as a preliminary to further research on sensory information processing in the auditory system.
-
ItemField potentials in cat auditory nuclei in response to frequency and amplitude modulated sound( 1972)This study was undertaken to determine how the field potentials recorded from the cochlear nucleus, inferior colliculus, and primary and secondary auditory cortices varied for different modes of frequency and amplitude modulated sound. The sound was presented to anaesthetized animals as a burst of five consecutive modulation envelopes. It had modulation rates which varied from 10- to 80- Hz, and depths of 10%, 50% and 100%. The field potentials were summed over 63 stimulus presentations, and then a spectral analysis was carried out on the result. The evoked responses produced in the various nuclei and by different stimulus parameters were compared using a coherence function.