Effects of lung volume on the glottal voice source

According to experience in voice therapy and singing pedagogy, breathing ha bits can be used to modify phonation, although this relationship has never been experimentally demonstrated. In the present investigation we examine i f lung volume affects phonation. Twenty-four untrained subjects phonated at different pitches and degrees of vocal loudness at different lung volumes. Mean subglottal pressure was measured and voice source characteristics wer e analyzed by inverse filtering, The main results were that with decreasing lung volume, the closed quotient increased, while subglottal pressure, pea k-to-peak flow amplitude, and glottal leakage tended to decrease. In additi on. some estimates of the amount of the glottal adduction force component w ere examined. Possible explanations of the findings are discussed.