Saxophonists tune vocal tracts
DOI: 10.1063/1.4796798
Saxophone great John Coltrane had a sound that is instantly recognizable to an experienced listener. His distinctive style arose in part from resonances in the frequency-dependent acoustic impedance (proportional to sound pressure) of his throat and mouth. Of course, the saxophone, which typically has a sharp impedance peak near the frequency of the note being played, also makes an important contribution. For some 25 years, acousticians and musicians alike have debated the vocal tract’s influence on an instrument’s sound. Now, Jer Ming Chen and colleagues at the University of New South Wales in Sydney, Australia, have addressed the question quantitatively—at least for the tenor saxophone, whose innards are big enough to house the researchers’ measuring equipment. The Sydney group determined that in the tenor’s lower range, resonances in the saxophone’s impedance are much stronger than those in a musician’s vocal tract. So the tract resonance need not be, and typically is not, tuned to the note sounded. But the strength of the instrument’s resonances decreases as the frequency of the note increases. To play a note in the so-called altissimo range, which comprises notes higher than the instrument was designed to play, the vocal-tract resonance needs to be significantly stronger than the instrument’s. And to tune the tract resonance to those super-high frequencies is a challenge—one met by the professional saxophonists but not by the amateurs in the study. (
