Background: An extensive body of literature indicates that cochlear implants (CIs) are effective
in supporting speech perception of persons with severe to profound hearing losses
who do not benefit to any great extent from conventional hearing aids. Adult CI recipients
tend to show significant improvement in speech perception within 3 mo following implantation
as a result of mere experience. Furthermore, CI recipients continue to show modest
improvement as long as 5 yr postimplantation. In contrast, data taken from single
testing protocols of music perception and appraisal indicate that CIs are less than
ideal in transmitting important structural features of music, such as pitch, melody,
and timbre. However, there is presently little information documenting changes in
music perception or appraisal over extended time as a result of mere experience.
Purpose: This study examined two basic questions: (1) Do adult CI recipients show significant
improvement in perceptual acuity or appraisal of specific music listening tasks when
tested in two consecutive years? (2) If there are tasks for which CI recipients show
significant improvement with time, are there particular demographic variables that
predict those CI recipients most likely to show improvement with extended CI use?
Research Design: A longitudinal cohort study. Implant recipients return annually for visits to the
clinic.
Study Sample: The study included 209 adult cochlear implant recipients with at least 9 mo implant
experience before their first year measurement.
Data Collection and Analysis: Outcomes were measured on the patient's annual visit in two consecutive years. Paired
t-tests were used to test for significant improvement from one year to the next. Those
variables demonstrating significant improvement were subjected to regression analyses
performed to detect the demographic variables useful in predicting said improvement.
Results: There were no significant differences in music perception outcomes as a function
of type of device or processing strategy used. Only familiar melody recognition (FMR)
and recognition of melody excerpts with lyrics (MERT-L) showed significant improvement
from one year to the next. After controlling for the baseline value, hearing aid use,
months of use, music listening habits after implantation, and formal musical training
in elementary school were significant predictors of FMR improvement. Bilateral CI
use, formal musical training in high school and beyond, and a measure of sequential
cognitive processing were significant predictors of MERT-L improvement.
Conclusion: These adult CI recipients as a result of mere experience demonstrated fairly consistent
music perception and appraisal on measures gathered in two consecutive years. Gains
made tend to be modest, and can be associated with characteristics such as use of
hearing aids, listening experiences, or bilateral use (in the case of lyrics). These
results have implications for counseling of CI recipients with regard to realistic
expectations and strategies for enhancing music perception and enjoyment.
Key Words
Cochlear implant - cognitive - music - speech perception
