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Using current steering to increase spectral resolution in CII and HiRes 90K users
Dawn Burton Koch1, Mark Downing, Mary Joe Osberger
1Advanced Bionics Corporation, Valencia, CA 91355, USA. dawnk@advancedbionics.com
Ear and Hearing
|May 15, 2007
Summary
Cochlear implants with current steering technology can create more spectral channels, enhancing pitch perception. This advancement in bionic ear technology may significantly improve speech and music understanding for users.
Area of Science:
- Audiology
- Biomedical Engineering
- Neuroscience
Background:
- The HiResolution Bionic Ear utilizes current steering to create virtual spectral channels.
- This involves simultaneous current delivery to adjacent electrodes to stimulate sites between contacts.
Purpose of the Study:
- To investigate the number of spectral channels resolvable by adult cochlear implant users with current steering.
- To assess the efficacy of current steering in enhancing spectral resolution in CII and HiRes 90K devices.
Main Methods:
- Adult users of CII and HiRes 90K cochlear implants participated.
- Loudness balancing and pitch ranking were performed on electrode pairs.
- An adaptive paradigm estimated intermediate pitch percepts with current steering.
Main Results:
- Data from 57 ears showed a range of 1 to 52 spectral channels per electrode pair.
- Average channels distinguished were 5.4 (basal), 8.7 (midarray), and 7.2 (apical).
- Estimated total potential channels per ear ranged from 8 to 466, averaging 93.
Conclusions:
- Current steering enables perception of additional spectral channels beyond fixed electrode stimulation.
- Cochlear implant users possess greater place-pitch capability than currently utilized.
- Future sound-processing strategies will leverage current steering for up to 120 channels, potentially improving speech and music perception.
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