Do trumpeters tune resonances of their vocal tract?

Abstract

In most wind instruments, the acoustic output is generated by airflow through a non-linear valve, whose sounding frequency is largely determined by resonances in the bore of the instrument (an acoustic duct downstream of the valve) and mechanical properties of the non-linear valve that converts DC to AC power. The player’s vocal tract (a second duct, upstream) also has acoustic resonances, which—in particular cases—play a significant role in performance technique. For example, when executing advanced techniques (e.g., pitch-bending, altissimo playing) on the clarinet and saxophone, we showed that expert control of vocal tract resonances is essential for performance [Chen et al., Science, 319, 726 (2008)]. To understand how such a tract-valve-bore system might interact during trumpet performance, we measured the acoustic impedance spectrum in seven trumpeters’ mouths as they played normal notes, high-register notes and while pitch-bending below and above the normal note. Unlike the behavior seen in saxophonists and clarinetists, none of the trumpeters studied showed any systematic adjustment of their vocal tract resonances to the notes played. The much greater control that trumpeters have over the natural frequency of the vibrating valve may explain the difference with clarinetists and saxophonists.