Evaluation of a Bio-inspired Coding Strategy for Cochlear Implant Users (EBCS)
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|ClinicalTrials.gov Identifier: NCT03726684|
Recruitment Status : Completed
First Posted : October 31, 2018
Last Update Posted : November 4, 2020
This study will determine the facilitation, refractoriness and spatial spread effects of auditory nerve fiber responses to electrical stimulation via a cochlear implant.
The performance of CI users in melody contour and speech recognition in noise tests with their own clinical sound processor and a MATLAB implementation of their coding strategy will be compared and a bioinspired coding strategy will be evaluated in comparison with the conventional ACE coding strategy.
|Condition or disease||Intervention/treatment||Phase|
|Hearing Loss, Complete||Device: Coding strategy for cochlear implants||Not Applicable|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||10 participants|
|Intervention Model:||Single Group Assignment|
|Intervention Model Description:||Single center, single-armed, parallel design with four laboratory sessions for CI subjects|
|Masking:||None (Open Label)|
|Primary Purpose:||Basic Science|
|Official Title:||Evaluation of a Bio-inspired Coding Strategy for Cochlear Implant Users|
|Actual Study Start Date :||July 2, 2018|
|Actual Primary Completion Date :||October 31, 2018|
|Actual Study Completion Date :||October 31, 2018|
Experimental: Coding strategy for cochlear implants
Measure neural responses of cochlear implant recipient Use measured values of refractoriness, spread of excitation and facilitation as parameters for a bioinspired coding strategy perform listening tests to compare new coding strategy with standard clinical coding strategy
Device: Coding strategy for cochlear implants
Comparison of two variations of a coding strategy based on electrophysiological objective measures with standard reference coding strategy
Other Name: Nucleus Cochlear Implant System
- Melody contour identification (MCI) test (% correct) [ Time Frame: 6 months ]In the MCI test, five different melody contour patterns with three tones in each pattern are presented in a five alternative forced choice paradigm. The complex tones are synthesized to resemble a clarinet musical instrument. Three separations of fundamental tone frequency varying from one to three semitones are used to vary the difficulties for pattern identification. Every pattern is repeated 10 times in random order which amounts to a total of 150 melody contour presentations per condition. Overall percent correct results and percent correct results for each of the five patterns are determined for the reference and the intervention conditions. Tests are performed with the conventional ACE coding strategy (reference condition) and the bioinspired coding strategy whose parameters are determined from electrophysiological measures of sound-evoked neural responses (intervention condition).
- Adaptive Oldenburg sentence test (OLSA) in noise (SRT in dB) [ Time Frame: 6 months ]The Adaptive Oldenburg sentence test (OLSA) in noise is used to evaluate speech intelligibility in a noisy environment. The noise level is kept constant at 65 dB sound pressure Level (SPL, in dB) and the speech level is adjusted adaptively to determine the speech reception threshold (SRT, in dB, for 50% speech intelligibility in noise). Lower SRT values indicate better speech recognition in noise. Tests are performed with the conventional ACE coding strategy (reference condition) and the bioinspired coding strategy whose parameters are determined from electrophysiological measures of sound-evoked neural responses (intervention condition).
- Time constants (usec) of recovery functions of electrically stimulated auditory nerve fibers, measured by electrically evoked compound action potential (ECAP) [ Time Frame: 6 months ]Time constants of recovery functions of electrically stimulated auditory nerve fiber groups can be assessed by ECAP measures through the cochlear implant for various electrode positions. Series of two stimulation pulses are presented whereby the interval between the two pulses is increased from 100 usec to 10'000 usec. The nerve response amplitude grows with increasing interpulse delay from zero up to a saturation level.
- Width of spread of excitation function (in mm) of electrically evoked compound action potential (ECAP) measures [ Time Frame: 6 months ]Spread of excitation (SOE) is measured with a fixed probe and varying masker electrodes along the electrode array. The width of exponentially fitted SOE curves (in mm) is the main measurement parameter. Outcome variations depend on the amount and distribution of remaining auditory nerve fibers and the geometrical properties of the implanted electrode array relative to the anatomical situation of the patient's inner ear.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03726684
|University Hospital Zurich, ENT Department|
|Zurich, Switzerland, 8091|
|Principal Investigator:||Norbert Dillier, PhD||University of Zurich|