Maximum Vocal Pitch Elevation and Swallowing: A Secondary Data Analysis Supporting Additional Shared Biomechanics and...

Reduced ability to raise vocal pitch has been associated with risk of aspiration in some populations. However, the mechanisms driving this association are understudied. This secondary data analysis aims to add to our knowledge on the shared and distinct biomechanics of swallowing and maximum vocal pitch elevation.

We used existing data from the study of Venkatraman et al. (2020) on 10 healthy younger (age range: 19-23, M = 21) and eight older (age range: 65-79; M = 73) adults who completed maximum pitch elevation and swallow tasks under videofluoroscopy. A MATLAB tracking tool and computational analysis of swallowing mechanics was used to analyze five elements of pharyngeal swallowing biomechanics (anterior and superior hyoid excursion, laryngeal elevation, pharyngeal shortening, tongue base retraction, head/neck extension). Canonical variate analysis (CVA) determined differences associated with task and age. Post hoc discriminant function analyses (DFAs) compared the events between tasks in each group.

CVA revealed that 63.9% of variance was accounted for by task (D = 3.46, p < .0001) and 35.5% by age (D = 1.92, p < .0001). Across age, DFAs indicated similar anterior hyoid excursion and laryngeal elevation between tasks, but greater superior hyoid excursion during swallows, replicating earlier findings. We also found greater base of tongue retraction during swallows than maximum pitch and greater pharyngeal shortening during maximum pitch elevation compared to swallows across groups (D = 5.38, p < .0001).

Maximum pitch elevation and swallowing require similar anterior hyoid and laryngeal excursion. Added to the novel finding of greater pharyngeal shortening during pitch elevation, we indicate that pitch glides may be a mechanism for targeting pharyngeal dysphagia and warrant further investigation.