Perception of wet vocal quality in identifying penetration/aspiration during swallowing

In the present study, the authors investigated the association between wet vocal quality (WVQ) and prandial material in the larynx during phonation. The presence of such material is indicative of oropharyngeal dysphagia and results from entry of material into the laryngeal vestibule during swallowing. The primary aim of the study was to determine whether clinicians reliably perceive WVQ during phonation when prandial material is in the larynx.

Seventy-eight subjects underwent videofluoroscopic swallow study, and simultaneous recording of time-linked videofluoroscopic and acoustic data was conducted during postswallow phonation. Experienced dysphagia clinicians then rated randomized audio samples for presence or absence of WVQ.

WVQ is not reliably perceived by clinicians when material is present in the larynx in the region of the glottis during phonation, and there is a high degree of interrater variability for perceptual judgments of wetness.

Material in the larynx during phonation may result in multiple voice quality percepts, and even experienced clinicians may not be adept at identifying the perceptual consequences of this. Observation of laryngeal physiology during voicing when material is in the larynx using vocal tract imaging can improve reliability in the identification of wet vocal quality.