Aging and the influence of contextual contrast on vowel identification

This study examines possible differences between young and older adult listeners in the effect of contextual contrast on vowel identification using a vowel anchoring procedure. All listeners identified a 7-step [i]-[I] continuum under both an equiprobable control condition and an anchoring condition (in which one endpoint stimulus occurred four times more often than any other single stimulus token). Phoneme boundaries in the anchoring condition shifted toward the anchor endpoint, as expected, for both groups, but there was a significant effect of age when [i] served as the anchor. Evidence of an increase in response bias for older adult listeners was also found.