Graeme Clark Collection
Permanent URI for this collection
Search Results
1 - 10 of 14
-
ItemA multiple-channel cochlear implant: an evaluation using nonsense syllables( 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.
-
ItemSpeech processing for a multiple-electrode cochlear implant hearing prosthesis( 1980)Abstract not available due to copyright.
-
ItemPerception of connected speech without lipreading, using a multi-channel hearing prosthesis( 1986)Four of 13 totally deaf patients implanted with the Nucleus multi-channel hearing prosthesis at the University of Melbourne have demonstrated the ability to understand connected speech without lipreading or other visual cues. These patients were able to repeat verbatim unknown material read by a tester at rates of up to 35 words per minute. They were also able to understand an average of 78%, of key word, in everyday sentences in ideal acoustic conditions and 51% of equivalent material over the telephone. These results show that with a good proportion of postlingually deaf patients the multi-channel hearing prosthesis can not only act as an aid to lipreading. but also restore effective speech understanding without lipreading.
-
ItemTelephone use by a multi-channel cochlear implant patient: an evaluation using open-set CID sentences(Cambridge University Press, 1985)A totally deaf person with a multiple-channel cochlear prosthesis obtained open-set speech discrimination using the telephone. CID Everyday Sentences were presented by telephone to the patient, who repeated an average of 21 per cent of key words correctly on the first presentation, and 47 per cent when a repeat of the sentences was permitted. This result is consistent with the patient's reports of telephone usage.
-
ItemThe multi-channel cochlear implant( 1984/85)The multi-channel cochlear implant codes sounds on the bases of rate and place pitch. Experimental studies on animals and patients have shown it is difficult for electrical stimulation to code rate pitch above about 200-400 pulses/second. Therefore to convey as much information about speech as possible it is necessary to produce multi-channel stimulation or place pitch so that the important frequency cues in vowels and consonants can be perceived by the patient.
-
ItemClinical trial of a multi-channel cochlear prosthesis: results on 10 postlingually deaf patients( 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.
-
ItemA lip-reading assessment for profoundly deaf patients(Cambridge University Press, 1983)To understand spoken sentences, first the acoustic information is processed, and secondly linguistic knowledge is applied (Fry, 1961; Kalikow et al., 1977). The more the spoken message contains linguistic redundancies in the form of lexical, syntactical and semantic constraints, the less the listener needs to rely on processing the details of the acoustic signal. For normal listening conditions there is usually enough information available to make an unambiguous decision about the spoken message. However, when the acoustic signal is degraded, more reliance is placed on the context in which the message was spoken (Miller et al., 1951). For some hearing-impaired individuals the auditory signal is permanently degraded. In addition, if people are totally or profoundly deaf, speech is usually perceived via lip-reading alone. This is usually difficult because not all phonemes can be clearly distinguished visually. For example, some phonemes form homophenous groups, i.e. they look the same on the lips; such a group would be the bilabial plosives and nasal /p, b, m/. Since the information reaching the individual is incomplete, greater reliance must also be placed on linguistic skills and on the context in which the message is spoken.
-
ItemInitial results for six patients with a multiple-channel cochlear prosthesis(Monash University Press, 1983)A total of eight patients have been assessed with the multi-channel cochlear prosthesis at the University of Melbourne. The first two patients were implanted with a prototype device in 1978 and 1979, and their results with various speech evaluation procedures have been reported and summarized in detail elsewhere (Clark & Tong, 1982). Briefly, these results indicated that some very significant benefit could be obtained for these patients when using the cochlear prosthesis with external speech processing, particularly when using the device in conjunction with lipreading. It was also shown that some significant understanding of speech was possible without lipreading (open-set) for both patients, although this was fairly limited.
-
ItemClinical trial of a multiple-channel cochlear prosthesis: an initial study in four patients with profound total hearing loss( 1983)The clinical trial of a multiple-channel cochlear prosthesis was undertaken in four patients with postlingual deafness and profound total hearing loss. The results of open-set speech tests confirmed that, using electrical stimulation alone, one patient could have a meaningful conversation with resorting to lipreading (for example, this patient uses the prosthesis to converse with her husband on the telephone). The results of closed-set speech tests also suggested that a multiple-channel stimulator is more effective than a single-channel one in conveying speech information. The cochlear prosthesis was especially effective in all four patients when it was used in conjunction with lipreading, and speech-tracking tests showed that the patients could combine the information obtained from both electrical stimulation and lipreading.
-
ItemThe preliminary clinical trial of a multichannel cochlear implant hearing prosthesis( 1983)Abstract not available due to copyright.