A morphological and acoustic study on the effect of a trumpet player's vocal tract

Abstract

A morphological and acoustic study is presented to examine the role of the vocal tract in playing the trumpet. Preliminary results obtained from one professional player are shown and the effectiveness of the method is demonstrated. Images of the vocal tract with a resolution of 0.5 mm (2 mm in thickness) were recorded with magnetic resonance imaging to observe tongue posture and to estimate the vocal-tract area function during actual trumpet performance. The input impedance was then calculated for the player's air column, including both the supra- and sub-glottal tracts, using an acoustic tube model that also considers wall losses. Finally, a time-domain blowing simulation was performed with a lip vibration model (Adachi and Sato, J.A.S.A. 99, 1200-1209, 1996). In this simulation, the oscillating frequency of the lips was slightly affected by using different shapes of the vocal tract measured for the player. In particular, when the natural frequency of the lips was gradually increased, the transition to higher modes occurred at different frequencies for different vocal-tract shapes. Furthermore, simulation results showed that the minimum blowing pressure required to attain lip oscillation can be reduced by properly adjusting the vocal-tract shape.