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Updated: May 11, 2026
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Performing Intracochlear Electrocochleography During Cochlear Implantation
Published on: March 8, 2022
Threshold levels of dual electrode stimulation in cochlear implants
Jorien Snel-Bongers1, Jeroen J Briaire, Erika H van der Veen
1ENT-department, Leiden University Medical Centre, PO box 9600, 2300, RC, Leiden, The Netherlands, j.snel-bongers@lumc.nl.
Summary
Dual electrode stimulation in cochlear implants effectively creates intermediate pitches at low levels. This study found no significant threshold differences, suggesting current steering eliminates the need for corrections in hearing restoration.
Area of Science:
- Biomedical Engineering
- Neuroscience
- Audiology
Background:
- Current steering in cochlear implants typically focuses on high loudness levels.
- Previous research has not extensively explored current steering at low stimulation thresholds.
Purpose of the Study:
- To investigate the efficacy of dual electrode stimulation at low levels in cochlear implants.
- To determine requirements for correcting threshold variations using current steering.
- To compare psychophysical data with computational modeling results.
Main Methods:
- Determined threshold levels using current steered signals across 7 coefficients (α) and 4 electrode pairs.
- Conducted psychophysical experiments with 12 postlingually deafened cochlear implant users.
- Utilized a computer model with 3 neural morphologies for simulation.
Main Results:
- Psychophysical data showed no significant difference between physical contact and intermediate percept thresholds at low levels.
- Computational models predicted threshold drops between contacts, observed in 5 subjects with wider electrode spacing.
- Threshold dips were linked to longer deafness duration and specific neural morphologies in the model.
Conclusions:
- Dual electrode stimulation at low levels appears effective, potentially reducing the need for threshold corrections.
- Computational models suggest surviving neural structures influence threshold perception in long-term deafness.
- Findings indicate that most spiral ganglion cells in long-term deafness retain peripheral processes but lack unmyelinated terminals.
