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Performing Repeated Intraoperative Impedance Telemetry Measurements during Cochlear Implantation
Published on: August 4, 2023
Within- and across-channel gap detection in cochlear implant listeners
1Department of Otolaryngology - Head & Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7070, USA. jhg@med.unc.edu
The Journal of the Acoustical Society of America
|February 6, 2008
Summary
Cochlear implant users show impaired temporal gap processing, similar to acoustic hearing. This suggests that the cochlea is not the primary limitation for gap detection in these users.
Area of Science:
- Auditory Neuroscience
- Audiology
- Biomedical Engineering
Background:
- Cochlear implants (CIs) aim to restore hearing by bypassing damaged cochlear structures.
- Temporal processing, crucial for speech understanding, is a known challenge for CI users.
- Understanding temporal gap processing in CI users is vital for improving device performance.
Purpose of the Study:
- To investigate within- and across-electrode-channel temporal gap processing in MED-EL COMBI 40+ cochlear implant users.
- To compare across-ear gap duration discrimination (GDD) and gap detection (GD) performance with acoustic hearing.
- To determine if central auditory system factors limit temporal processing in CI users.
Main Methods:
- Experiment 1: Tested across-ear GDD in four bilateral CI users, assessing thresholds for different marker configurations.
- Experiment 2: Evaluated the effect of envelope fluctuation bandwidth and compression on monaural GD in five CI users.
- Utilized MED-EL COMBI 40+ cochlear implant systems for all participants.
Main Results:
- Across-ear GDD thresholds were elevated compared to monaural, within-electrode-channel thresholds.
- Gap detection performance worsened with narrower noise bands (50 Hz vs. 300 Hz) and improved with envelope compression.
- Performance declines were observed for channel-asymmetric markers.
Conclusions:
- Temporal gap processing in cochlear implant users is influenced by factors central to the cochlea, mirroring findings in acoustic hearing.
- The results suggest that central auditory system limitations, rather than the implant's electrode-channel processing, are key.
- Further research into central auditory processing strategies may enhance CI speech perception.
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