Maria Chantziara – Master’s Thesis, July 2015
Ongoing scientific research concerning the mechanism of the singing voice, is conducted the last years. The identification of the basic parameters that control the functionality of the vocal system, would give singers the possibility to produce desirable sounds with less effort and in a healthy way. Complete Vocal Technique is a singing method which is based on the anatomy and physiology of the vocal system. This technique suggests four vocal modes with which the human instrument can produce sounds, independently the singing style of the singer.
The shape of the vocal tract during the phonation of the modes and the strength of the harmonics was defined. The geometrical data were obtained from previous research us- ing Magnetic Resonance scanning. Already recorded data were processed. The results showed that each vocal mode has a different epilarynx tube, which seems to influence the strength of the coupling between the source and the filter. The analysis of the recorded data, showed evidence that there are two possible modes between the non metallic and full metallic modes. The fact that different vowels were used for each mode, renders the con- clusion preliminary and suggests further experimental approach. The vocal folds model is a symmetrical mechanical system. Each vocal fold consists of two masses, springs and dampers. The system self oscillates without the presence of the vocal tract. The obtained vocal tract configurations for four modes were coupled with the vocal folds model. The tension parameter was adjusted to shift the fundamental frequency of the phonation and the initial displacement of the masses triggered the oscillation. An interaction between the vocal folds and the vocal tract was observed since the strength of the harmonics was shifted when different modes were simulated. However, many of the harmonics seem underestimated compared to the measurements. The deviation from the measurements is attributed to the simplified model that was used. Unfortunately, the time restriction did not leave space for further analysis and the implementation of a more complex model.