Effect of age on F0 difference limen and concurrent vowel identification.
OBJECTIVE
To investigate the effect of age on voice fundamental frequency (F0) difference limen (DL) and identification of concurrently presented vowels.


METHODS
Fifteen younger and 15 older adults with normal audiometric thresholds in the speech range participated in 2 experiments. In Experiment 1, F0 DLs were measured for a synthesized vowel. In Experiment 2, accuracy in identifying concurrently presented vowel pairs was measured. Vowel pairs were formed from 5 synthesized vowels with F0 separations ranging from 0 to 4 semitones.


RESULTS
Younger adults had smaller (better) F0 DLs than older adults. For the older group, age was significantly correlated with F0 DLs. Younger adults identified concurrent vowels more accurately than older adults. When the vowels in the pairs had different formants, both age groups benefited similarly from F0 separation. Interestingly, when both constituent vowels had identical formants, F0 separation was deleterious, especially for older adults. Pure-tone average threshold did not correlate significantly with either F0 DL or accuracy in concurrent vowel identification.


CONCLUSIONS
Age-related declines were confirmed for F0 DLs, identification of concurrently spoken vowels, and benefit from F0 separation between vowels with identical formants. This pattern of findings is consistent with age-related deficits in periodicity coding.
Vongpaisal
Tara
T
Department of Psychology, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada.
Pichora-Fuller
Margaret Kathleen
MK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001309:Auditory Threshold; D006801:Humans; D007206:Individuality; D010700:Phonetics; D013067:Speech Perception