The Trajectory of Voice Onset Time with Vocal Aging

TL;DR

This study analyzes long-term changes in Voice Onset Time from Queen Elizabeth's speeches, revealing a narrowing variation range and slight mean reduction over fifty years, likely due to aging-related muscle changes.

Contribution

It introduces a statistical model to analyze long-term Voice Onset Time trends, controlling for various factors, and uncovers subtle aging effects on speech acoustics.

Findings

Variation range of Voice Onset Time has narrowed over fifty years.

Mean Voice Onset Time has slightly decreased.

Diminishing exertion and muscle contraction influence long-term Voice Onset Time patterns.

Abstract

Vocal aging, a universal process of human aging, can largely affect one's language use, possibly including some subtle acoustic features of one's utterances like Voice Onset Time. To figure out the time effects, Queen Elizabeth's Christmas speeches are documented and analyzed in the long-term trend. We build statistical models of time dependence in Voice Onset Time, controlling a wide range of other fixed factors, to present annual variations and the simulated trajectory. It is revealed that the variation range of Voice Onset Time has been narrowing over fifty years with a slight reduction in the mean value, which, possibly, is an effect of diminishing exertion, resulting from subdued muscle contraction, transcending other non-linguistic factors in forming Voice Onset Time patterns over a long time.