Age-Related Temporal Processing Deficits in Word Segments in AdultCochlear-Implant Users

摘要

Aging may limit speech understanding outcomes in cochlear-implant (CI) users.Here, we examined age-related declines in auditory temporal processing as apotential mechanism that underlies speech understanding deficits associated withaging in CI users. Auditory temporal processing was assessed with acategorization task for the words dish and ditch (i.e., identify each token asthe word or ) on a continuum ofspeech tokens with varying silence duration (0 to 60 ms) prior to the finalfricative. In Experiments 1 and 2, younger CI (YCI), middle-aged CI (MCI), andolder CI (OCI) users participated in the categorization task across a range ofpresentation levels (25 to 85 dB). Relative to YCI, OCI required longer silencedurations to identify ditch and exhibited reduced ability to distinguish thewords dish and ditch (shallower slopes in the categorization function).Critically, we observed age-related performance differences only at higherpresentation levels. This contrasted with findings from normal-hearing listenersin Experiment 3 that demonstrated age-related performance differencesindependent of presentation level. In summary, aging in CI users appears todegrade the ability to utilize brief temporal cues in word identification,particularly at high levels. Age-specific CI programming may potentially improveclinical outcomes for speech understanding performance by older CIlisteners.