Characterizing speech rhythm using spectral coherence between jaw displacement and speech temporal envelope

Abstract

Lower modulation rates in the temporal envelope (ENV) constitute the rhythmic frames in speech and are crucial for speech comprehension in terms of neuronal entrainments at δ- and θ-rates. The jaw plays the role of a carrier articulator producing the low-frequency modulations in this process. This paper introduces a method to examine the joint roles of jaw oscillation and ENV in formulating rhythmic frames using spectral coherence. Relative powers in the frequency bands corresponding to the δ- and θ-oscillations were quantified and regressed on utterance duration. Two English corpora were analyzed for the proof of concept.

Characterizing first and second language rhythm in English using spectral coherence between temporal envelope and mouth opening-closing movements

“…To integrate both temporal modulation and the opening and closing cycles of the mouth for the characterization of the rhythmic frame, spectral coherence has been used. 77,78 The coherence is calculated from the spectra of two signals to show the connectivity between them in terms of their correlation in the frequency domain. It combines interrelated signals into one system.…”

“…[63][64][65][66]77 It has further been demonstrated that in the coherence, the frequency density in the lower range (0.5-3 Hz) and higher range (3)(4)(5)(6)(7)(8)(9) are different between longer and shorter utterances. 78 Spectral coherences have also been calculated between the surface electromyographic signals at the lips and the jaw and the temporal envelopes; they were also effective to outline the rhythmic structure in speech. 79…”