Multi-Dimensional Variation in Adult Speech as a Function of Age

Abstract

We present a multidimensional acoustic report describing variation in speech productions on data collected from 500 francophone adult speakers (20 to 93 y.o.a.) as a function of age. In this cross-sectional study, chronological age is considered as a continuous variable while oral productions, in reading and speech-like tasks, are characterized via 22 descriptors related to voice quality, pitch, vowel articulation and vocalic system organization, time-related measures and temporal organization, as well as maximal performances in speech-like tasks. In a first analysis, we detail how each descriptor varies according to the age of the speaker, for male and female speakers separately. In a second analysis, we explore how chronological age is, in turn, predicted by the combination of all descriptors. Overall, results confirm that with increasing age, speakers show more voice instability, sex-dependent pitch changes, slower speech and articulation rates, slower repetition rates and less complexity effects in maximal performance tasks. A notable finding of this study is that some of these changes are continuous throughout adulthood while other appear either at old age or in early adulthood. Chronological age appears only moderately indexed in speech, mainly through speech rate parameters. We discuss these results in relation with the notion of attrition and with other possible factors at play, in an attempt to better capture the multidimensional nature of the notion of “age”.

A Longitudinal Study of Speech Acoustics in Older French Females: Analysis of the Filler Particle euh across Utterance Positions

“…One frequently-discussed aspect of aging that we omit here is slowed speech or articulation rate. Readers are referred to the comprehensive studies of Schötz (2006) and Fougeron et al (2021) for results on duration and other measures not included here.…”

“…Some aspects of chronological change, especially across speakers, could reflect sound change (e.g., Reubold et al 2010) and/or stylistic factors that may change with age and interact with gender. As one possible example, Fougeron et al (2021) observed that measures of F1 and F2 ranges differed in older males and females: Males showed no significant changes in F1 range with age, whereas females did; conversely, F2 ranges changed with age in males but not females.…”

“…They similarly observed a decrease in f0 (to about age 60), followed by a slight increase. Finally, Fougeron et al (2021) measured f0 in a sentence for 265 women, with fuller representation (37 or more speakers) per decade age 60 or older. They observed that f0 decreased to about age 40 and then remained stable.…”

“…We are focusing on a decade in the lifespan of the older generation (all of them aged 70+ at the second time point). As Fougeron et al (2021) state, dynamics of vocal aging do not unfold evenly over the lifespan.…”

“…Our acoustic analysis covers formants (F1, F2) and fundamental frequency (f0), which have been widely studied, and voice quality, which has been assessed less frequently (but see the recent work by Fougeron et al 2021;Karlsson and Hartelius 2021). All parameters can reflect physical effects of aging but may also be conditioned by prosody, specifically whether the filler occurs pre-pausally, post-pausally, or within a speech unit.…”