Effects of vocal warm-up, vocal loading, and tube phonation on phonation and collision threshold pressures
2012 (English)In: The Voice Foundation's 41st annual Symposium: Care of the Professional Voice / [ed] Robert Sathaloff, Philadelphia: The Voice Foundation , 2012Conference paper (Other academic)
Collision threshold pressure (CTP) is defined as the lowest subglottal pressure producing vocal fold collision. It has been measured in three studies, to analyze the effects of (1) vocal warm-up, (2) vocal loading and (3) the voice therapy method resonance tube phonation, which implies phonation into a tube, the end of which is placed a few cm under water. Also, phonation threshold pressure (PTP) was determined. This threshold pressure, however, although more commonly used, is often difficult to measure; the coefficient of variation has been found mostly to be higher for PTP than for CTP.
Before and after data for CTP and PTP were determined from audio, electroglottographic (EGG) and pressure signals. Subjects repeated the syllable /pa:/ with gradually decreasing vocal loudness at several fundamental frequencies. Subglottal pressure was estimated from oral pressure during the p-occlusion. CTP was determined using EGG or dEGG spike amplitude as criteria of vocal fold collision, while vocal fold vibration for PTP measurement was determined from the audio signal.
The first investigation, with 15 amateur singers, suggested that vocal warm-up tended to lower both CTP and PTP. The effect of vocal loading, studied in seven subjects two of whom had trained voices, was that CTP and PTP rose, especially in the untrained voices. Resonance tube phonation exercise (tube length 27 cm, Æ 8 mm) caused an increase of CTP and PTP in 12 mezzo-soprano voices, with different levels of voice training. The effect on both CTP and PTP was greater in less trained singers, and was perceived as an improvement in a pair-wise comparison listening test with seven voice experts.
The three studies support the conclusion that CTP can be used as a valuable complement to or replacement of PTP.
Place, publisher, year, edition, pages
Philadelphia: The Voice Foundation , 2012.
IdentifiersURN: urn:nbn:se:liu:diva-79342OAI: oai:DiVA.org:liu-79342DiVA: diva2:540742
The Voice Foundation's 41st annual Symposium, May 30 - June 3, 2012, Philadelphia, Pennsylvania, USA
ProjectsAlternative measures of Phonation. Collision threshold pressure and wavegrams