Respiratory and articulatory influences on inhalation noise during speech

Abstract

During speech production, individuals inhale more deeply and rapidly compared to non-speaking inspiration. Such inspirations are also more frequently audible than their non-speech counterparts. To what extent do the acoustic characteristics of inhalation noise reflect respiratory contributions versus other articulatory mechanisms? To gain insight into this question, here we relate acoustics, captured using a head-mounted microphone, with kinematic data collected via respiratory inductance plethysmography (RIP) and optopalatography (OPG). The OPG system permits measurement of lip movements (displacement and velocity), tongue-palate contacts, and midsagittal distance when the tongue has no contact with the palate. Custom-made palates, including both contact sensors as well as optical sensors, were obtained for eight typical female speakers of German. Speech was recorded in normal and loud conditions. In this exploratory analysis, we anticipate that (a) louder speech will be accompanied by deeper, more rapid inhalations; and (b) greater articulatory opening during the inhalation phase; (c) the magnitude of lip aperture will be correlated with inspiration-excited first formant values; and (d) both supralaryngeal and respiratory displacements and velocities will be reflected in the inhalation noise characteristics. That is, speech inspiration, like speech itself, will demonstrate regular correspondences between physiological actions and the acoustic output.