Threshold and channel interaction in cochlear implant users: Evaluation of the tripolar electrode configuration

2007 ◽  
Vol 121 (3) ◽  
pp. 1642-1653 ◽  
Author(s):  
Julie Arenberg Bierer
Keyword(s):  
Cochlear Implant ◽  
Electrode Configuration ◽  
Channel Interaction

Compensation for channel interaction in a simultaneous cochlear implant coding strategy

2013 ◽  
Vol 133 (6) ◽  
pp. 4124-4132 ◽  
Author(s):  
Paul Bader ◽  
Mathias Kals ◽  
Reinhold Schatzer ◽  
Andreas Griessner ◽  
Clemens Zierhofer
Keyword(s):  
Cochlear Implant ◽  
Channel Interaction ◽  
Coding Strategy

scholarly journals An Attempt to Improve Bilateral Cochlear Implants by Increasing the Distance between Electrodes and Providing Complementary Information to the Two Ears

2010 ◽  
Vol 21 (01) ◽  
pp. 052-065 ◽  
Author(s):  
Richard S. Tyler ◽  
Shelley A. Witt ◽  
Camille C. Dunn ◽  
Ann Perreau ◽  
Aaron J. Parkinson ◽  
...  
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Speech Processing ◽  
Processing Strategy ◽  
Bilateral Cochlear Implants ◽  
Channel Interaction ◽  
Consonant Recognition ◽  
Bilateral Cochlear Implant ◽  
Input Spectrum

Objectives: The purpose of this investigation was to determine if adult bilateral cochlear implant recipients could benefit from using a speech processing strategy in which the input spectrum was interleaved among electrodes across the two implants. Design: Two separate experiments were conducted. In both experiments, subjects were tested using a control speech processing strategy and a strategy in which the full input spectrum was filtered so that only the output of half of the filters was audible to one implant, while the output of the alternative filters was audible to the other implant. The filters were interleaved in a way that created alternate frequency “holes” between the two cochlear implants. Results: In experiment one, four subjects were tested on consonant recognition. Results indicated that one of the four subjects performed better with the interleaved strategy, one subject received a binaural advantage with the interleaved strategy that they did not receive with the control strategy, and two subjects showed no decrement in performance when using the interleaved strategy. In the second experiment, 11 subjects were tested on word recognition, sentences in noise, and localization (it should be noted that not all subjects participated in all tests). Results showed that for speech perception testing one subject achieved significantly better scores with the interleaved strategy on all tests, and seven subjects showed a significant improvement with the interleaved strategy on at least one test. Only one subject showed a decrement in performance on all speech perception tests with the interleaved strategy. Out of nine subjects, one subject preferred the sound quality of the interleaved strategy. No one performed better on localization with the interleaved strategy. Conclusion: Data from this study indicate that some adult bilateral cochlear implant recipients can benefit from using a speech processing strategy in which the input spectrum is interleaved among electrodes across the two implants. It is possible that the subjects in this study who showed a significant improvement with the interleaved strategy did so because of less channel interaction; however, this hypothesis was not directly tested.

Efficacy of a Cochlear Implant Simultaneous Analog Stimulation Strategy Coupled with a Monopolar Electrode Configuration

2005 ◽  
Vol 114 (11) ◽  
pp. 886-893 ◽  
Author(s):  
Li Xu ◽  
Teresa A. Zwolan ◽  
Catherine S. Thompson ◽  
Bryan E. Pfingst
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Speech Processing ◽  
Dynamic Range ◽  
Recognition Performance ◽  
Electrode Configuration ◽  
Processing Strategy ◽  
Open Set ◽  
Hearing In Noise ◽  
Noise Test

Objectives: The present study was performed to evaluate the efficacy and clinical feasibility of using monopolar stimulation with the Clarion Simultaneous Analog Stimulation (SAS) strategy in patients with cochlear implants. Methods: Speech recognition by 10 Clarion cochlear implant users was evaluated by means of 4 different speech processing strategy/electrode configuration combinations; ie, SAS and Continuous Interleaved Sampling (CIS) strategies were each used with monopolar (MP) and bipolar (BP) electrode configurations. The test measures included consonants, vowels, consonant-nucleus-consonant words, and Hearing in Noise Test sentences with a +10 dB signal-to-noise ratio. Additionally, subjective judgments of sound quality were obtained for each strategy/configuration combination. Results: All subjects but 1 demonstrated open-set speech recognition with the SAS/MP combination. The group mean Hearing in Noise Test sentence score for the SAS/MP combination was 31.6% (range, 0% to 92%) correct, as compared to 25.0%, 46.7%, and 37.8% correct for the CIS/BP, CIS/MP, and SAS/BP combinations, respectively. Intersubject variability was high, and there were no significant differences in mean speech recognition scores or mean preference ratings among the 4 strategy/configuration combinations tested. Individually, the best speech recognition performance was with the subject's everyday strategy/configuration combination in 72% of the applicable cases. If the everyday strategy was excluded from the analysis, the subjects performed best with the SAS/MP combination in 37.5% of the remaining cases. Conclusions: The SAS processing strategy with an MP electrode configuration gave reasonable speech recognition in most subjects, even though subjects had minimal previous experience with this strategy/configuration combination. The SAS/MP combination might be particularly appropriate for patients for whom a full dynamic range of electrical hearing could not be achieved with a BP configuration.

scholarly journals Cochlear Implant: Effect of the Number of Channel and Frequency Selectivity on Speech Understanding in Noise Preliminary Results in Simulation with Normal-Hearing Subjects

2020 ◽  
Vol 81 (1-4) ◽  
pp. 17-23
Author(s):  
P.A. Cucis ◽  
C. Berger-Vachon ◽  
R. Hermann ◽  
H. Thaï-Van ◽  
S. Gallego ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Signal To Noise Ratio ◽  
Normal Hearing ◽  
Measuring Channel ◽  
Frequency Selectivity ◽  
Speech Understanding ◽  
Preliminary Results ◽  
Channel Interaction ◽  
Speech Understanding In Noise ◽  
The Impact

The cochlear implant is the most successful implantable device for the rehabilitation of profound deafness. However, in some cases, the electrical stimulation delivered by the electrode can spread inside the cochlea creating overlap and interaction between frequency channels. By using channel-selection algorithms like the “nofm” coding-strategy, channel interaction can be reduced. This paper describes the preliminary results of experiments conducted with normal hearing subjects (n = 9). Using a vocoder, the present study simulated the hearing through a cochlear implant. Speech understanding in noise was measured by varying the number of selected channels (“nofm”: 4, 8, 12 and 16of20) and the degree of simulated channel interaction (“Low”, “Medium”, “High”). Also, with the vocoder, we evaluated the impact of simulated channel interaction on frequency selectivity by measuring psychoacoustic tuning curves. The results showed a significant average effect of the signal-to-noise ratio (p < 0.0001), the degree of channel interaction (p < 0.0001) and the number of selected channels, (p = 0.029). The highest degree of channel interaction significantly decreases intelligibility as well as frequency selectivity. These results underline the importance of measuring channel interaction for cochlear implanted patients to have a prognostic test and to adjust fitting methods in consequence. The next step of this project will be to transpose these experiments to implant users, to support our results.

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