Accelerometer-Based Respiratory Measurement During Speech

Accelerometer-based respiratory monitoring is a recent area of research based on the observation of small rotations at the chest wall due to breathing. Previous studies of this technique have begun to address some sources of interference e.g. subject movements, but have not investigated operation during speech production when breathing patterns are known to be substantially different to normal respiration. We demonstrate measurement of speech breathing with a wireless tri-axial accelerometer in a synchronously captured dataset, including annotated audio and electro-magnetic articulograph data. We find agreement between peaks in the accelerometer-derived rotation signal and manually annotated breath timings, and correlation between peak rotations and the duration of audible in breaths. In speech breathing the rotation rate signal does not appear to be a good proxy for airflow rate as previously suggested, and instead seems to better reflect the role of specific muscles around the accelerometer location. We conclude that the method can be usable during speech breathing, but that this difference should be considered. The method has some advantages for speech breathing research due to its unobtrusive nature.