Characterization of Upper Esophageal Sphincter Pressures Relative to Vocal Acoustics.

Abstract

Strength of vocal fold adduction has been hypothesized to be a critical factor influencing voice quality, but has been difficult to measure directly during phonation. Recent work has suggested that UES pressure, which can be easily assessed, increases with stronger vocal fold adduction, raising the possibility that UES pressure might indirectly reflect vocal fold adduction strength. However, concurrent UES pressure and voice quality have not previously been examined across different vocal tasks. Doing so may offer insights into the potential use of UES pressure for relative quantification of the strength of vocal fold adduction, and how this might contribute to voice quality across different vocal tasks. We assessed UES pressure relative to voice quality in 32 vocally healthy adults during sustained vowels, whispered sentences, and spoken sentences. Smoothed cepstral peak prominence (CPPs) and low-to-high spectral energy ratio (LHR) were derived from the acoustic signal as measures of voice quality. After controlling for resting UES pressure, age, and sex, we observed significant negative correlations between UES pressure and CPPs, and a significant positive correlation between UES pressure and LHR. UES pressures were significantly higher during spoken sentences than whispered sentences and sustained vowels.. Measuring UES pressure relative to acoustic measures of voice quality is a novel methodology for studying upper aerodigestive tract physiology during phonation, and has potential to enhance understanding of voice disruption in clinical populations. Clinical implications and considerations for implementation are discussed.