Evaluating hearing performance with cochlear implants within the same patient using daily randomization and imaging based fitting - The ELEPHANT study

Background : Prospective research in the field of cochlear implants is hampered by methodological issues and small sample sizes. The ELEPHANT study presents an alternative clinical trial design with a daily randomized approach evaluating individualized tonotopical CI fitting. Methods : A single blinded, daily randomized clinical trial will be implemented to evaluate a new imaging based CI mapping strategy. A minimum of 20 participants will be included from the start of the rehabilitation process with a 1-year follow-up period. Based on a post-operative cone beam CT scan (CBCT), mapping of electrical input will be aligned to natural place-pitch arrangement in the individual cochlea. Adjustments to the CI’s frequency allocation table will be made so electrical stimulation of frequencies will match as closely as possible with corresponding acoustic locations in the cochlea. A randomization scheme will be implemented whereby the blinded subject crosses over between the experimental and standard fitting program on a daily basis, and thus effectively acts as his own control, followed by a period of free choice between both maps to incorporate patient preference. With this new approach the occurrence of a first-order carryover effect and a limited sample size is addressed. Discussion : The experimental fitting strategy is thought to give rise to a steeper learning curve, result in a better performance in challenging listening situations, improve sound quality, complement better with residual acoustic hearing in the contralateral ear and win the preference of CI-recipients. Concurrently, the suitability of the novel trial design will be considered in investigating these hypotheses. Trial registration : ClinicalTrials.gov: NCT03892941, registered 27 March 2019, https://clinicaltrials.gov/ct2/show/NCT03892941

Music Perception in Adult Users of Cochlear Implants: A Brief Review

Although cochlear implants (CIs) can provide good speech understanding in quiet, in general, users of CIs have shown poor music perception performance, particularly with regard to pitch (and hence melody). This is primarily due to the limited ability of CI processing strategies and electric stimulation to provide place pitch and fine structure information from the original input signal to the auditory nervous system of the user. Approaches such as current focusing, current steering, enhanced amplitude modulation cues, and optic stimulation have been shown or theorized to assist in music perception, as have musical training programs. This article is a brief review of research related to music perception in adults with CIs, specifically their rhythm, pitch, and melody perception performance; processing strategies that have been or are being developed which might improve their music perception performance; and music training programs that have been shown to improve their music perception performance.