Control of the vocal tract when experienced saxophonists perform normal notes and overtones

Acoustic measurement of the vocal tract proved that experienced saxophonists tune their vocal tract during advanced performances to effectively influence the vibration frequency of the reed (Scavone et al., J. Acoust. Soc. Am., 123, 2391-2400 (2008); Chen et al., J. Acoust. Soc. Am., 129, 415-426 (2011)). To understand how the shape of the vocal tract is altered, the vocal tracts of experienced saxophonists were scanned in three dimensions with magnetic resonance imaging while they played the instrument using different pitches with normal and overtone techniques. The scanned images demonstrated that the tongue was located posteriorly in the vocal tract for low notes; however, it moved forward when the participants produced overtones. The input impedance was then calculated for the players' air columns, including both the supra- and sub-glottal tracts, using an acoustic tube model. When the tongue moved forward to produce overtones, both the frequency and amplitude of the second impedance peak increased, suggesting an effective acoustic influence of the vocal behavior on the vibrating reed. The first impedance peak was less variable, regardless of the significant change in the vocal-tract shape for different notes.