Music Appreciation After Cochlear Implantation

Cochlear implants are medical devices that restore a remarkable degree of hearing to people who would otherwise be profoundly deaf. These devices generally restore enough hearing that recipients can understand spoken speech even in noisy environments. However, most recipients express dissatisfaction with music. This proposal centers on understanding the challenges that implant users face and the strategies that they adopt as they learn to appreciate music with this new way of hearing. The proposed research is organized into three aims: Aim 1: Characterize music appreciation after cochlear implantation. The proposed research balances qualitative and quantitative methods to examine the emergence of music appreciation after cochlear implantation. Qualitative methods will include semi-structured interviews and focus groups designed to clarify the obstacles that implant users face as they learn to appreciate music with their new sense of hearing. Quantitative methods include surveys of music appreciation and quality of life, and auditory assessments of music and speech perception. The primary hypothesis is that music appreciation is predictive of key domains of quality of life including positive affect and well-being, and satisfaction with social roles and activities. Aim 2: Determine if pitch training improves cochlear implant speech comprehension. The proposed research tests for a causal relationship between pitch salience and key features of speech perception including talker discrimination, prosody detection, and speech recognition in competing speech. Cochlear implant users and their normal-hearing peers will take part in a crossover study to determine if pitch training improves aspects of music and speech perception compared to a visual task used as a control. The primary hypothesis is that pitch training will improve speech comprehension for cochlear implant users, but not for their normal-hearing peers. Aim 3: Test the limits of pitch coding in cochlear implants. The proposed research bypasses conventional sound processing to study the salience of pitch provided by electrode location and stimulation rate. These two stimulation cues are the primary cues for providing a sense of pitch to cochlear implant users. New research has shown that implant users are able to learn to use this information to hear pitch with better resolution far better than previously thought. The primary hypothesis is that cochlear implant users have a latent ability to hear pitch associated with stimulation rate, but that they require experience to learn how to hear this new information. In each aim, psychophysical methods are combined with measures of EEG and near-infrared spectroscopy. The results will establish the importance of music training for improving cochlear implant outcomes, both in terms of hearing abilities and quality of life. The results will lead to changes in how music is encoded into implant stimulation, providing better outcomes for recipients. More generally, this project will shape understanding of neural coding of music and its role in social adjustment following traumatic experiences.