Speech perception results in children implanted with Clarion® devices: Hi-resolution™ and standard resolution modes

Bosco, Ersilia; D'Agosta, Luciana; Mancini, Patrizia; Traisci, Gabriella; D’Elia, Chiara; Filipo, R.

doi:10.1080/00016480410023010

Cited by 19 publications

(16 citation statements)

References 14 publications

(17 reference statements)

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“…This results in the well-known phenomenon of "channel interaction." Channel interaction can lead to unpredictable loudness fluctuations, and smearing of the spatial representation of spectrum ͑Shannon, 1983b; Fu and Nogaki, 2005;Boex et al, 2003;Stickney et al, 2006͒. Almost all successful stimulation strategies in clinical use today circumvent channel interaction by using sequential pulsatile stimulation ͑Skinner, 1994; Wilson et al, 1991;Skinner et al, 2002;Bosco et al, 2005͒. Such strategies deliver stimulation through only one ͑usually monopolar͒ channel at any given instant.…”

Section: Introductionmentioning

confidence: 98%

Focused intracochlear electric stimulation with phased array channels

Honert

Kelsall

2007

The Journal of the Acoustical Society of America

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A method is described for producing focused intracochlear electric stimulation using an array of N electrodes. For each electrode site, N weights are computed that define the ratios of positive and negative electrode currents required to produce cancellation of the voltage within scala tympani at all of the N-1 other sites. Multiple sites can be stimulated simultaneously by superposition of their respective current vectors. The method allows N independent stimulus waveforms to be delivered to each of the N electrode sites without spatial overlap. Channel interaction from current spread associated with monopolar stimulation is substantially eliminated. The method operates by inverting the spread functions of individual monopoles as measured with the other electrodes. The method was implemented and validated with data from three human subjects implanted with 22-electrode perimodiolar arrays. Results indicate that (1) focusing is realizable with realistic precision; (2) focusing comes at the cost of increased total stimulation current; (3) uncanceled voltages that arise beyond the ends of the array are weak except when stimulating the two end channels; and (4) close perimodiolar positioning of the electrodes may be important for minimizing stimulation current and sensitivity to measurement errors.

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Section: Introductionmentioning

confidence: 98%

Focused intracochlear electric stimulation with phased array channels

Honert

Kelsall

2007

The Journal of the Acoustical Society of America

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“…HiRes was investigated in several monaural studies ͑e.g., Frijns et al, 2002;Filipo et al, 2004;Bosco et al, 2005͒, showing some improvements, particularly a better speech recognition in noise, compared to pulse rates in the region of 1500 pps. However, it is difficult to interpret these results in the context of bilateral stimulation and effects on fine structure ITD sensitivity.…”

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confidence: 94%

Effects of interaural time differences in fine structure and envelope on lateral discrimination in electric hearing

Majdak

Laback

Baumgartner

2006

The Journal of the Acoustical Society of America

102

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Bilateral cochlear implant (CI) listeners currently use stimulation strategies which encode interaural time differences (ITD) in the temporal envelope but which do not transmit ITD in the fine structure, due to the constant phase in the electric pulse train. To determine the utility of encoding ITD in the fine structure, ITD-based lateralization was investigated with four CI listeners and four normal hearing (NH) subjects listening to a simulation of electric stimulation. Lateralization discrimination was tested at different pulse rates for various combinations of independently controlled fine structure ITD and envelope ITD. Results for electric hearing show that the fine structure ITD had the strongest impact on lateralization at lower pulse rates, with significant effects for pulse rates up to 800 pulses per second. At higher pulse rates, lateralization discrimination depended solely on the envelope ITD. The data suggest that bilateral CI listeners benefit from transmitting fine structure ITD at lower pulse rates. However, there were strong interindividual differences: the better performing CI listeners performed comparably to the NH listeners.

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“…Children were tested making use of our standard speech perception test battery (Bosco et al, 2004), Auditory Speech Sound Evaluation (A §E) tests for discrimination and identification of phonemes (Govaerts et al, 2006), non-verbal IQ and attention span. The A §E discrimination test was administered choosing a subset of contrast phonemes: /u/-/a/, /u/-/i/, /z/-/s/ and /v/-/z/, both in quiet and in noise with SNR +10.…”

Section: Methodsmentioning

confidence: 99%