Speech under physical stress: A production-based framework

This paper examines the impact of physical stress on speech. The methodology adopted here identifies inter-utterance breathing (IUB) patterns as a key intermediate variable while studying the relationship between physical stress and speech. Additionally, this work connects high-level prosodic changes in the speech signal (energy, pitch, and duration) to the corresponding breathing patterns. Our results demonstrate the diversity of breathing and articulation patterns that speakers employ in order to compensate for the increased body oxygen demand. Here, we identify the normalized value of breathing energy rate (proportional to minute volume) acquired from a conventional as well as physiological microphone as a reliable and accurate estimator of physical stress. Additionally, we also show that the prosodic patterns (pitch, energy, and duration) of high-level speech structure shows good correlation with the normalized-breathing energy rate. In this manner, the study establishes the interconnection between temporal speech structure and physical stress through breathing.