The relationship of voice onset time and Voice Offset Time to physical age

In a speech signal, Voice Onset Time (VOT) is the period between the release of a plosive and the onset of vocal cord vibrations in the production of the following sound. Voice Offset Time (VOFT), on the other hand, is the period between the end of a voiced sound and the release of the following plosive. Traditionally, VOT has been studied across multiple disciplines and has been related to many factors that influence human speech production, including physical, physiological and psychological characteristics of the speaker. The mechanism of extraction of VOT has however been largely manual, and studies have been carried out over small ensembles of individuals under very controlled conditions, usually in clinical settings. Studies of VOFT follow similar trends, but are more limited in scope due to the inherent difficulty in the extraction of VOFT from speech signals. In this paper we use a structured-prediction based mechanism for the automatic computation of VOT and VOFT. We show that for specific combinations of plosives and vowels, these are re-latable to the physical age of the speaker. The paper also highlights the ambiguities in the prediction of age from VOT and VOFT, and consequently in the use of these measures in forensic analysis of voice.