Cochlear implant re-mapping deactivates poorly placed electrodes to improve spectral resolution.

Evidence

If a poor ENI arises due to an underlying neural dead region, the transmission of information in that frequency channel could be impeded; if a poor ENI arises due to the presence of broad electrical fields, this will lead to corruption of channel specific information. For both cases it could be beneficial to deactivate electrodes, however when doing so frequency information is re-allocated to other electrodes making analysis bands broader and distorting frequency-to-electrode mapping. These effects are small for individual electrode deactivation but can be substantial for deactivation of multiple electrodes, potentially resulting in poorer precision of information transmission; a completely opposite effect to that intended. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2051

Various approaches have been explored to look at the effects of re-mapping cochlear implants (CIs) to overcome the problems associated with neural dead regions or poor electrode placement (electrode-neuron interface (ENI)). The mapping interventions have typically explored ways to identify electrodes for de-activation using Computerized Tomography (CT), threshold profiling with focussed stimulation, detection of modulation and pitch-based electrode discrimination. Electrodes indicated as being in a region with a poor ENI have typically been deactivated with the intention of improving spectral resolution by reducing overlapping electrode stimulation patterns. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2052

Categorization

• DEFINE: Explains what electrode-neuron interface (ENI) means and how it causes channel corruption through broad electrical fields.
• XREF: Connects to the reader’s broader hearing physiology and implant signal-processing interests.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 2051; Dijk, Pim van, Physiology, Psychoacoustics and…, 2052