# Perceptual Adaptation Following Cochlear Implantation

> **NIH NIH R01** · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · 2024 · $682,911

## Abstract

Cochlear implants (CIs) are neural prosthetic devices that successfully restore hearing. However,
understanding speech from CIs does not happen instantaneously. Speech understanding and sound quality do
improve after initial CI activation, but the process may take weeks, months, or even years. A major element of
this adaptation process in postlingually deaf CI users (those who learned oral language before losing their
hearing) involves overcoming anatomical frequency mismatch, the discrepancy between the normal
cochlear frequency-place function and that imposed by the CI. This can result in perceptual frequency
mismatch, defined as the difference between pitch percepts elicited by a sound in a normal ear and a CI-
stimulated ear. Importantly, higher levels of perceptual frequency mismatch are associated with poorer speech
perception. Fortunately, the human auditory system is plastic and perceptual frequency mismatch decreases
over time. The current standard of care is based on the assumption that such adaptation can completely
compensate for anatomical frequency mismatch. However, the literature and our pilot data indicate that this
assumption is often incorrect.
An alternative approach to improve speech perception and sound quality is to use frequency-place maps that
match the physiological frequency-place function, with the goal of making adaptation unnecessary. This
approach may also be suboptimal. Given typical insertion depth of CI electrodes, matching the physiological
frequency-place function can only be done at the cost of failing to deliver low-frequency information. This
unexplored tradeoff will be studied in the aims that follow. Our overall goal is to study the extent and possible
limitations of the adaptation process that underlies speech perception improvement, and to test personalized
medicine approaches that seek to accelerate and improve adaptation outcomes after CI activation.
Aim 1 will study adaptation to frequency mismatch in single-sided deaf (SSD) CI users longitudinally, starting at
CI activation. SSD-CI users are ideal for this purpose as they can provide a precise comparison between
normal acoustic stimulation and CI stimulation. This will be done using two innovative tools: one that is speech-
based, and another one that represents a generalization of electroacoustic pitch matching. Aim 2 will examine
adaptation over time using a broader set of central and peripheral measures in a more traditional population of
CI users who lack usable residual hearing. Lastly, and as a complement to the observational studies in Aim 1,
Aim 3 will evaluate different interventional approaches to overcome frequency mismatch in CI users, including
SSD CI users (Aim 3a) and CI users without usable residual hearing (Aim 3b).
The proposed experiments will provide foundational information about the nature, extent, and potential
limitations of perceptual adaptation after CI activation, as well as a path for translation of these results to
clinic...

## Key facts

- **NIH application ID:** 10942879
- **Project number:** 1R01DC021980-01
- **Recipient organization:** NEW YORK UNIVERSITY SCHOOL OF MEDICINE
- **Principal Investigator:** Mario A Svirsky
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $682,911
- **Award type:** 1
- **Project period:** 2024-08-26 → 2029-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10942879

## Citation

> US National Institutes of Health, RePORTER application 10942879, Perceptual Adaptation Following Cochlear Implantation (1R01DC021980-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10942879. Licensed CC0.

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