| Abstract | Objective:
Semi occluded vocal tract exercises (SOVTs) are used as a vocal warmup in classical voice studios as a way to maximize vocal output while minimizing vocal use. By creating an occlusion in the vocal tract, SOVTs introduce varying degrees of air pressure in the supraglottal airway. The purpose of the study reported here was to measure and compare oral air pressure, airflow, and glottographic measures for both lip trill and raspberry productions.
Methods:
The project had one subject (the first author), a trained singer in a variety of styles. The abstract here reports preliminary data on raspberry productions. A Glottal Enterprises aerodynamic system was used for oral air pressure and airflow recording, a Kay 6103 electroglottograph, a DATAQ system for A/D conversion, and Sigplot and Excel to analyze the recordings.
Results:
For a production of 5 raspberry sequences (on a single inspiration), the findings are the following for smoothed signals: (1) oral air pressure was strongly inversely related to airflow (r = -0.92), suggesting that pressure increased and airflow decreased with greater lip closure during the raspberry; (2) following minimum airflow, there was a double maximum airflow pulse and double decrement of air pressure (a decrease of approximately 20% and 35% in pressure); (3) the DC EGG waveform height was inversely related to air pressure; (4) EGG CQ correlated negatively to air pressure (r=-0.61) – when oral air pressure was higher (9-11 cm H2O) the CQ value was lower (c. 0.40), and when pressure was lower (7-9 cm H2O) the CQ value was higher (c. 0.5), suggesting greater glottal closure during reduced supraglottal air pressure (perhaps due to increased transglottal pressure and thus longer glottal closure).
Conclusions:
The results suggest that there a sensible relationship among lip region opening, lip region vibration, oral air pressure, airflow, and glottographic measures, and understanding these relationships may shed further light on the pedagogical effectiveness of this type of SOVTs. This study will be expanded to include more parameters and lip trills prior to the Symposium.
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