Indications And Results of the Multichannel Cochlear Implant

Pialoux, P; Ch, Chouard; Meyer, B.; Fugain, C

doi:10.3109/00016487909126405

Cited by 29 publications

(11 citation statements)

References 1 publication

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“…The choice of this strategy was justified on the basis of psychophysical results. These results {Simmons, 1966; House, 1976; Eddington et al, 1978;Burian et al, 1979;Pialoux et al, 1979;andTong et al, 1979, 1982) showed that pitch, sharpness, and spectral color produced by activating different intracochlear electrodes in postlingually' deaf patients were found to vary in accordance with the tonotopic organization of the cochlea, although this tonotopic orderliness was not apparent in prelingually deaf patients {for example, subject JB reported in Eddington et al, 1978). Pitch was also found to increase with electric pulse rate and loudness with current level.…”

Section: Recent Studies From Various Research Centers Havementioning

confidence: 59%

Psychophysical studies evaluating the feasibility of a speech processing strategy for a multiple-channel cochlear implant

Tong

Blamey

Dowell

et al. 1983

The Journal of the Acoustical Society of America

131

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This paper reports further psychophysical studies on a multiple-channel cochlear implant patient evaluating the feasibility of a speech processing strategy which converts the acoustic fundamental frequency to electric repetition rate, the second-formant frequency to electrode position, and the acoustic amplitude to current level. The first four studies evaluated the use of a special pulse pattern to minimize the loudness variation with electric repetition rate. The chosen pulse pattern consisted of multiple pulses occurring in the first half of each repetitive period (MPP) in contrast to the more conventional pattern with a single pulse per period (SPP). The results showed that MPP approximately equalized the loudness variation with repetition rate. The dynamic range of current, the pitch variation with repetition rate, and the difference limens for repetition rate were found to be similar to MPP and SPP. Two other studies investigated interaction between electrode position and repetition rate (RR). The first of these showed that the patient could make use of information provided by rising or falling RR trajectories superimposed on individual electrodes or electrode trajectories as an indicator of the direction of intonation variation. The second of these studies showed that the dissimilarities amongst the hearing sensations produced by steady-state stimuli differing in electrode position and repetition rate were characterized by two perceptual components, relating to the two electric parameters, respectively.

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Section: Recent Studies From Various Research Centers Havementioning

confidence: 59%

Psychophysical studies evaluating the feasibility of a speech processing strategy for a multiple-channel cochlear implant

Tong

Blamey

Dowell

et al. 1983

The Journal of the Acoustical Society of America

131

View full text Add to dashboard Cite

show abstract

“…Intra-cochlear multiple-channel electrical stimulation has recently been used by a number of research centers as a means of helping to alleviate profound or total hearing loss (Simmons et al, 1979a;House, 1976;Ed-, dington et al, 1978;Burian et al , 1979;Pialoux et al , 1979;Merzenieh et al, 1979). In selecting a speech processing strategy that will restore useful hearing in patients, it is important to examine the nature of the hearing sensations produced by multiple-channel electrical stimulation.…”

Section: Introductionmentioning

confidence: 96%

Psychophysical studies for two multiple-channel cochlear implant patients

Tong

Clark

Blamey

et al. 1982

The Journal of the Acoustical Society of America

110

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Psychophysical studies were conducted on two multiple-channel cochlear implant patients to examine the nature of the hearing sensations produced by electrical stimulation of auditory nerve fibers using electrodes at different sites in the scala tympani (one electrode at a time). Both time-invariant stimuli, whose parameter values did not vary in time, and time-varying stimuli, specified by a linear variation in parameter values, were used. A sharpness ranking study using time-invariant signals suggested that the hearing sensations produced by different electrodes varied from dull to sharp in an apical to basal direction in the scala tympani. A categorization study showed that the hearing sensations produced by two adjacent electrodes (1.5 mm apart) were rarely confused for a restricted range of time-invariant pulse rates. Discriminability studies by a same-different procedure for stimuli with pulse rate below 250 pps showed: (1) relative difference limens of 6% to 12% for time-invariant pulse rates, and 9% and 13% for time-varying pulse rates; (2) stimuli with time-varying electrode position differing in the direction of electrode trajectory were readily discriminated; and (3) the discrimination of time-varying pulse rates deteriorated with decreases in the duration of the variation, while the discriminability of single-electrode trajectories was the same for the three durations: 25, 50, and 100 ms. A speech processing strategy was also proposed on the bases of these results.

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“…Even though the early devices stimulated the auditory nerve with one electrode only, some lucky patients managed to hear again and even understand speech. Nowadays, it is technologically possible to use more than one electrode, in order to stimulate more of the thousands of neurons the auditory nerve is made of [33,9]. However, the more electrodes, the more parameters to tune.…”

Section: Cochlear Implantsmentioning

confidence: 99%