Abstract

Purpose: This exploratory study aims to investigate variations in voice production in the presence of background noise (Lombard effect) in individuals with non-phonotraumatic vocal hyperfunction (NPVH) and individuals with typical voices using acoustic, aerodynamic, and vocal fold vibratory measures of phonatory function.Method: Nineteen participants with NPVH and 19 participants with typical voices produced simple vocal tasks in three sequential background conditions: baseline (in quiet), Lombard (in noise), and recovery (5 min after removing the noise). The Lombard condition consisted of speech-shaped noise at 80 dB SPL through audiometric headphones. Acoustic measures from a microphone, glot-tal aerodynamic parameters estimated from the oral airflow measured with a cir-cumferentially vented pneumotachograph mask, and vocal fold vibratory param-eters from high-speed videoendoscopy were analyzed.Results: During the Lombard condition, both groups exhibited a decrease in open quotient and increases in sound pressure level, peak-to-peak glottal air-flow, maximum flow declination rate, and subglottal pressure. During the recov-ery condition, the acoustic and aerodynamic measures of individuals with typi-cal voices returned to those of the baseline condition; however, recovery mea-sures for individuals with NPVH did not return to baseline values.Conclusions: As expected, individuals with NPVH and participants with typical voices exhibited a Lombard effect in the presence of elevated background noise levels. During the recovery condition, individuals with NPVH did not return to their baseline state, pointing to a persistence of the Lombard effect after noise removal. This behavior could be related to disruptions in laryngeal motor control and may play a role in the etiology of NPVH.Supplemental Material: https://doi.org/10.23641/asha.20415600