Analysis and perception of speech under physical task stress

It is known that speech under physical task stress degrades speech system performance. Therefore, an analysis of speech under physical task stress is performed across several parameters to identify acoustic correlates. Formal listener tests are also performed to determine the relationship between acoustic correlates and perception. To verify the statistical significance of all results, student-t statistical tests are applied. It was found that fundamental frequency decreases for many speakers, that utterance duration increases for some speakers and decreases for others, and that the glottal waveform is quantifiably different for many speakers. Perturbation of two speech features, fundamental frequency and the glottal waveform, is applied in listener tests to quantify the degree to which these features convey physical stress content in speech. Finally, the enhanced understanding of physical task stress speech provided here is discussed in the context of speech systems.