title: Jet offset, harmonic content, and warble in the flute.
abstract: The effects of jet offset in the flute, directing the jet above or below the edge, were explored by two distinct means-experiments with a Boehm flute sounded by an artificial blower, and time domain simulation. Very large changes in harmonic content and dynamics were observed, changing greatly with blowing pressure. Warble, a modulation of the tone at frequencies of the order of 20 Hz, was observed both in the experiment and in the simulation. The phenomenon is explained as a beat between the frequency of a second harmonic generated by nonlinearity in the jet current and a neighboring partial sustained by jet feedback near the second mode resonance. A second type of warble, in which amplitude modulation occurs in all partials but with different phases, is yet to be explained.
authors.affiliation: coltmanjw@verizon.net
authors.forename: John W
authors.initials: JW
authors.lastname: Coltman
mesh_terms: D000162:Acoustics; D000392:Air Movements; D003198:Computer Simulation; D005583:Fourier Analysis; D006801:Humans; D008046:Lip; D008962:Models, Theoretical; D009146:Music; D013997:Time Factors