Peripheral and Central Influences on Auditory Temporal Processing & Speech Perception in Older Cochlear Implantees

Peripheral and Central Contributions to Auditory Temporal Processing Deficits and Speech Understanding in Older Cochlear Implantees

Older adults who use cochlear implants to address hearing loss show wide variation in benefit. This research investigates the role of normal aging, the health of peripheral and central auditory pathways, and positioning of the cochlear implant electrode array in contributing to this variability. A range of input types from simple auditory signals to spoken sentences is used to examine these questions.

This research aims to understand age-related temporal processing in older cochlear-implant (CI) users. The overall objective is to disentangle the peripheral and central contributions to age-related temporal processing deficits in this population. The central hypothesis is that age-related speech perception deficits are explained by unique contributions from peripheral and central auditory functions, significantly affecting outcomes in older CI users.

The central hypothesis will be tested by determining (1) the extent to which temporal processing of simple signals from single-electrode stimulation can be explained by aging and the peripheral electrode-to-neural interface; (2) the extent to which speech perception can be explained by aging and the peripheral electrode-to-neural interface; (3) the extent and manner in which central auditory compensation overcomes peripheral processing deficits that contribute to age-related performance declines in CI subjects.

Outcome measures collected in this project include behavioral measures of speech and auditory perception and electrophysiological responses.

Also collected are questionnaire-based reports of history of CI device use, cognitive screening measures, and imaging-based information regarding electrode placement in the cochlea.

Better understanding of the locus of age-related temporal processing deficits in this population will aid in developing age-specific guidance regarding CI candidacy, programming, and rehabilitation, thereby improving expected benefit and quality of life.

For Cochlear Implant arm:

Inclusion Criteria:

• cochlear implant in one or both ears
• post-lingual onset of deafness
• 1+ years cochlear implant experience
• use of Cochlear-brand implants
• implanted after 2004

Exclusion Criteria:

• use of non-Cochlear-brand cochlear implants
• no use of oral language
• pregnant women are not eligible for the imaging portion of the study.
• residual acoustic hearing with unaided thresholds <90 dB HL at more than two standard audiometric frequencies
• other known disability or neurological disorder

For Typical Hearing arm:

Inclusion Criteria:

• audiometrically normal hearing, near-normal hearing, or mild/moderate hearing loss.

Exclusion Criteria:

• severe hearing loss
• history of neurological disorders
• history of middle-ear disorders