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Evaluation of a Bio-inspired Coding Strategy for Cochlear Implant Users (EBCS)

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ClinicalTrials.gov Identifier: NCT03726684
Recruitment Status : Recruiting
First Posted : October 31, 2018
Last Update Posted : October 31, 2018
Sponsor:
Information provided by (Responsible Party):
University of Zurich

Brief Summary:

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

  Show Detailed Description

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Study Type : Interventional  (Clinical Trial)
Estimated 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
Estimated Primary Completion Date : October 31, 2018
Estimated Study Completion Date : October 31, 2018

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
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




Primary Outcome Measures :
  1. 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).


Secondary Outcome Measures :
  1. 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).

  2. 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.

  3. 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.



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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • having Nucleus System 4, System 5, System 6 or System 7 sound processor
  • having 20 or more active electrodes
  • using one of these implant types: System 4, System 5, System 6, System 7
  • using ACE coding strategy
  • speech recognition score of at least 70% on Oldenburg Speech Test (OLSA) in quiet
  • ability to perform an adaptive speech recognition test in noise
  • experience with their CI for at least six months
  • ability for speech understanding in the presence of competing noise without any assistance from lip-reading
  • ability to hear differences between musical notes at least for the easiest condition (3 semitones difference between successive notes in a pattern)
  • ability to provide subjective feedback in a certain listening situation
  • proficiency in reading and writing in German

Exclusion Criteria:

  • Acute inflammation or pain in head-/neck area
  • Dizziness
  • Other known illness which would prevent regular participation in test sessions
  • Age of participants < 18 years
  • Age of participants > 80 years
  • Non-standard clinical sound processor program

Information from the National Library of Medicine

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


Contacts
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Contact: Andrea Kegel, MA +41 44 255 5808 andrea.kegel@usz.ch
Contact: Sonia Tabibi, MSc +41 44 255 5808 sonia.tabibi@usz.ch

Locations
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Switzerland
University Hospital Zurich, ENT Department Recruiting
Zurich, Switzerland, 8091
Contact: Andrea Kegel, MA    +41 44 2555801    andrea.kegel@usz.ch   
Contact: Sonia Tabibi, MSc    +41 44 2555801    sonia.tabibi@usz.ch   
Sponsors and Collaborators
University of Zurich
Investigators
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Principal Investigator: Norbert Dillier, PhD University of Zurich

Publications:
Omran SA, Lai W, Dillier N. Pitch ranking, Melody contour and instrument recognition tests using two semitone frequency maps for Nucleus Cochlear Implants. EURASIP Journal on Audio, Speech, and Music Processing, 2011; 1-16.

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Responsible Party: University of Zurich
ClinicalTrials.gov Identifier: NCT03726684     History of Changes
Other Study ID Numbers: EBCS
First Posted: October 31, 2018    Key Record Dates
Last Update Posted: October 31, 2018
Last Verified: October 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Keywords provided by University of Zurich:
cochlear implant
coding strategy
objective measures
Additional relevant MeSH terms:
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Hearing Loss
Deafness
Hearing Disorders
Ear Diseases
Otorhinolaryngologic Diseases
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms