Jenny Iwarsson

Effects of lung volume on the glottal voice source

According to experience in voice therapy and singing pedagogy, breathing habits can be used to modify phonation, although this relationship has never been experimentally demonstrated. In the present investigation we examine if 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 were analyzed by inverse filtering. The main results were that with decreasing lung volume, the closed quotient increased, while subglottal pressure, peak-to-peak flow amplitude, and glottal leakage tended to decrease. In addition, some estimates of the amount of the glottal adduction force component were examined. Possible explanations of the findings are discussed.

Effects of lung volume on vertical larynx position during phonation

The vertical position of the larynx seems to be relevant to voice function. As a high vertical larynx position is often seen in hyperfunctional and strained voices, a lowering of a habitually elevated larynx is sometimes a specific goal in clinical voice therapy and different larynx-lowering exercises are used to achieve this goal. Earlier investigations have shown that pitch and to some extent also vocal loudness are relevant to vertical larynx position. In the present investigation, we examine if lung volume affects vertical larynx position. Using a multi-channel electroglottograph, the larynx position was measured in 29 healthy, vocally untrained subjects, who phonated at different lung volumes, pitches, and degrees of vocal loudness. The main results were that high lung volume was clearly associated with a lower larynx position as compared to low lung volume. In addition, vertical larynx position was strongly correlated with pitch. Both of these dependencies were shown to be stronger in males than in females. Our results suggest that lung volume is a factor that is highly relevant to larynx height in untrained subjects.

Significance of mechanoreceptors in the subglottal mucosa for subglottal pressure control in singers

According to Wyke and Kirchner (Wyke B, Kirchner J. Neurology of the larynx. In: Hinchcliffe R, Harrison D, eds. Scientific foundation of otolaryngology. London: William Heinemann Medical Books, 1976:546-66) mechanoreceptors in the subglottal mucosa play a significant role in the control of laryngeal muscle activity in response to changes of subglottal pressure during phonation. In singers this pressure is adapted not only to phonatory loudness but also to fundamental frequency. By spraying Xylocaine solution with a needle inserted into the trachea through the anterior gap between the cricoid and thyroid cartilages, the subglottal mucosa was anesthetized in three singers. The effects on subglottal pressure and fundamental frequency of this anesthesia were examined. The pressure effects varied between the subjects, whereas the fundamental frequency accuracy was adversely affected in all three subjects. The implications of these findings are discussed.

Estimated subglottal pressure in six professionalcountry singers

Estimates of subglottal pressure in six professional male country singers were obtained during the /p/ occlusion while the subjects spoke, sang a country tune, and sang the tune of the United States national anthem. The subglottal pressure values, which were very similar in both the speech-like and singing-mode syllables, usually measured below 45 cm of water column, but they ranged as high as 59 cm. The sound pressure level in singing was also measured and was lower than that discovered in classically trained singers at high subglottal pressures.

Breathing behaviors during speech in healthy females and patients with vocal fold nodules

The purpose of the present investigation was to compare 6 females with vocal nodules and 14 normal controls with regard to a number of respiratory parameters, sound pressure level (SPL) and fundamental frequency during five different speaking tasks. The hypothesis was that patients with vocal nodules differ from normal speakers with regard to respiratory behavior during speech. Lung volume changes were recorded by means of respiratory inductive plethysmography. The results were significantly influenced by the different tasks for many of the parameters. The results also indicate that the nodule patients had greater subglottal pressure, SPL and mean air flow, fewer syllables per breath group and shorter duration of inhalations than the controls. During spontaneous speech, the females with vocal nodules tended to initiate and terminate phonation at lower lung volumes than the controls and, in shouting, their average initiation lung volume was clearly lower as compared with those of the controls; thus, the pa...

Lung volume and phonation: a methodological study

Lung volume affects the tracheal pull which according to Zenker (1964) tends to widen the glottis and thus may affect phonation. In the present study five healthy subjects with untrained voices phonated at high and low lung volumes while rib cage and abdominal wall circumferences, subglottal pressure, larynx position and voice-source characteristics were determined. The results showed that subglottal pressure, larynx height, glottal compliance, i.e., the ratio flow-pulse area to subglottal pressure, and the closed quotient tended to vary with lung volume. The results suggest that the method can be used in a full scale investigation.