Music Perception in Older Adult Cochlear Implant Users: Evidence About Age-related Decline in Rapid Temporal Processing

Abstract

Age-related cognitive decline (ARCD) refers to deterioration of basic cognitive functions in normal human aging that mainly associates with areas of sensory processing, attention, memory, and executive control. Because listening to music involves a highly complex integration in various levels of cognitive processing that extend from basic auditrory fuctions to high-level feature extraction and emotional/aesthetic response, music listening tests have been frequently used in clinical reserch settings in the past two decades as a tool for screening areas of deficits in various kinds of pathological populations (e.g., hearing impaired, neurological patients, children with learning disabilities). There are two main reasons why assessing music listening abilities of older adult Cochlear Implant (CI) users is important for aging researchers. First, it shows how the combined influence of ARCD, and the reduced and/or distorted sensory information provided by a hearing implant may globally or selectively deteriorate an implantee's sensitivity to basic elements of music such as rhythm, melody, harmonic structure, and consonance/dissonance. Second, it provides evidence about cognitive domains or processes that display the greatest decline with age.In this study the effects of CI users’ chronological age on their performance on music listening tests were explored through the use of the MuSIC perception test battery, with special emphasis on the influence of aging in perceiving musical stimuli that require rapid temporal processing (e.g., rhythm patterns). Analysis is based on data from a recently completed European multicenter study on music perception in CI users wearing a MED-EL's PULSARCI100 or a SONATATI100 with an OPUS 2 audio processor (N = 81, age range: 21,2-82,3 years), and Normally Hearing (NH) adults (N = 46, age range: 21,1-58,8 years). Areas of music listening abilities that display noticeable declines in older implant users are highlighted by statistically comparing distributions of test scores among a subgroup of CI users over 60 years (N = 24), the subgroup of users younger than 60, and the group of NH controls. Resultsshowed that older adult CI users appear not to differ significantly from younger ones in processing low-level features of music such as pitch and timbre, although their accuracy is differentially affected in favor of the younger ones when listening tasks are complex and require rapid temporal processing of the stimuli, or attention switching between two or more sources of information (e.g., identification of individual musical instruments playing in ensemble). Aging also appears to negatively affect processing of rhythm patterns in music, a deficit likely attributable to general slowing of information processing in older adults, while, in contrast, processing of melodies and chord structures remains relatively intact.