Effect of Age on F^sub 0^ Difference Limen and Concurrent Vowel Identification

• Published in: Journal of speech, language, and hearing research Vol. 50; no. 5; p. 1139
• Main Authors: Vongpaisal, Tara, Pichora-Fuller, Margaret Kathleen
• Format: Journal Article
• Language: English
• Published: Rockville American Speech-Language-Hearing Association 01.10.2007
• Subjects: Adults; Aging (Individuals); Auditory Perception; Coding; Cues; Ears & hearing; Evidence; Frequencies; Intelligibility; Phonemes; Speech; Timing differences; Vowels; Word Recognition
• ISSN: 1092-4388; 1558-9102

To investigate the effect of age on voice fundamental frequency (F^sub 0^) difference limen (DL) and identification of concurrently presented vowels. Fifteen younger and 15 older adults with normal audiometric thresholds in the speech range participated in 2 experiments. In Experiment 1, F^sub 0^ 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 F^sub 0^ separations ranging from 0 to 4 semitones. Younger adults had smaller (better) F^sub 0^ DLs than older adults. For the older group, age was significantly correlated with F^sub 0^ 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 F^sub 0^ separation. Interestingly, when both constituent vowels had identical formants, F^sub 0^ separation was deleterious, especially for older adults. Pure-tone average threshold did not correlate significantly with either F^sub 0^ DL or accuracy in concurrent vowel identification. Age-related declines were confirmed for F^sub 0^ DLs, identification of concurrently spoken vowels, and benefit from F^sub 0^ separation between vowels with identical formants. This pattern of findings is consistent with age-related deficits in periodicity coding.