Loud voice during environmental noise exposure in patients with vocal nodules.

The aim was to investigate how female patients with vocal nodules use their voices when trying to make themselves heard over background noise. Ten patients with bilateral vocal fold nodules and 23 female controls were recorded reading a text in four conditions, one without noise and three with noise from cafés/pubs, played over loudspeakers at 69, 77 and 85 dBA. The noise was separated from the voice signal using a high-resolution channel estimation technique. Both patients and controls increased voice sound pressure level (SPL), fundamental frequency (F0), subglottal pressure (Ps) and their subjective ratings of strain significantly as a main effect of the increased background noise. The patients used significantly higher Ps in all four conditions. Despite this they did not differ significantly from the controls in voice SPL, F0 or perceived strain. It was concluded that speaking in background noise is a risk factor for vocal loading. Vocal loading tests in clinical settings are important and further development of assessment methods is needed.