Repeatability of the acoustic swallowing pattern in normal adults

The repeatability of the acoustic swallowing signal was evaluated in young, middle-aged, and elderly adults. Swallowing signals were audio-recorded on 3 alternate days, during trials of three consistencies: dry swallows, thin liquid swallows, and pudding consistency swallows. Analysis of overall swallow duration identified no significant age-group differences across experimental sessions and across viscosities. The finding that the acoustic signal is repeatable and similar across age groups was interpreted to reflect similar physiological mechanisms during the production of a swallow. The absence of an age effect in swallowing was assumed to be indicative of a high degree of motor stability in normal swallowing across adulthood. The importance of quantification and validity of normal swallowing sounds as a necessary first step in the clinical practice of cervical auscultation is emphasized.