Acoustic profiling of swallowing sounds of liquid associated with different bolus consistencies

Abstract

Cervical auscultation has been used as an augmentative procedure for swallowing examination in the clinical setting. Despite the reported usefulness of such technique in screening and preliminary assessment of swallowing, the usefulness of the procedure is controversial due to a lack of solid research findings, particularly in quantifying swallowing sounds. The present study attempted to acoustically document the characteristics of normal swallowing sound when swallowing food of different consistencies. Thirty healthy adult participants swallowed 5 mL boluses of different consistencies while the swallowing sounds were recorded by using an electronic wireless stethoscope. An array of measurements including duration, frequency, and intensity of the acoustic swallowing signals were obtained. Results indicated significant differences between duration of swallowing and consistencies, but not between genders. The results could serve as a reference for future research into normal swallowing across different bolus consistencies. In-depth comparison can be made to different dysphagic patients in the future.