Rotationnal and translational waves in a bowed string

Eric Bavu (1) , Manfred Yew (1) , Pierre-Yves Placais (1) , John Smith (1) , Joe Wolfe (1)

1 M.A.L - Music Acoustics Laboratory

We measure and compare the rotational and transverse velocity of a bowed string. When bowed by an experienced player, the torsional motion is phase-locked to the transverse waves, producing highly periodic motion. The spectrum of the torsional motion includes the fundamental and harmonics of the transverse wave, with strong formants at the natural frequencies of the torsional standing waves in the whole string. Volunteers with no experience on bowed string instruments, however, often produced non-periodic motion. We present sound files of both the transverse and torsional velocity signals of well-bowed strings. The torsional signal has not only the pitch of the transverse signal, but it sounds recognisably like a bowed string, probably because of its rich harmonic structure and the transients and amplitude envelope produced by bowing.

Mots clés: cordes; Music; violin; rotational; Helmholtz; bowed; frottees; rotationnelles; ISMA; ondes; Acoustics; waves; torsional; Acoustique; instrument; string

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

Eric Bavu, Manfred Yew, Pierre-Yves Placais, John Smith, Joe Wolfe. Rotationnal and translational waves in a bowed string. International Symposium on Musical Acoustics 2004, Apr 2004, Nara, Japan. ⟨hal-00004848⟩