Vocal aging effects on F0 and the first formant: A longitudinal analysis in adult speakers

This paper presents a longitudinal analysis of the extent to which age affects F0 and formant frequencies. Five speakers at two time intervals showed a clear effect for F0 and F1 but no systematic effects for F2 or F3. In two speakers for which recordings were available in successive years over a 50 year period, results showed with increasing age a decrease in both F0 and F1 for a female speaker and a V-shaped pattern, i.e. a decrease followed by an increase in both F0 and F1 for a male speaker. This analysis also provided strong evidence that F1 approximately tracked F0 across the years: i.e., the rate of change of (the logarithm of) F0 and F1 were generally the same. We then also tested that the changes in F1 were not an acoustic artifact of changing F0. Perception experiments with the main aim of assessing whether changes in F1 contributed to age judgments beyond those from F0 showed that the contribution of F1 was inconsistent and negligible. The general conclusion is that age-related changes in F1 may be compensatory to offset a physiologically induced decline in F0 and thereby maintain a relatively constant auditory distance between F0 and F1.