Saxophonists tune vocal tracts

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...