Investigation of the effect of upstream airways impedance on regeneration of lip oscillations in trombone performance

Vincent Freour (1) , Gary Scavone

1 Music Research Department

The role of the vocal tract in the regeneration of lip oscillations in brass instruments is uncertain though influence in the high register of the instrument seems plausible. In this study, we have developed a sensor which measures the variations of electrical conductance across the lips in brass instrument performance, and therefore enables the evaluation of the phase of the lip opening area. By combining this value with the phase of the acoustic pressures on the downstream and upstream sides of the lips, we investigate the nature of the coupling between the lips, the downstream air-column and the vocal-tract in trombone performers. This method allows for the study of vocal-tract tuning at the fundamental frequency with a high temporal resolution (within a tone), as well as characterization of the oscillatory mechanism of the lips (dominant outward versus dominant upward striking behaviour). Experimental results from a pool of trombone players are discussed in light of numerical simulations where a two-dimensional model of the vibrating lips is coupled to both a downstream and upstream reflectance.

Mots clés: Brass instruments; Vocal tract; auto-oscillations; Trombone

Domaines: Acoustique [physics.class-ph]

Vincent Freour, Gary Scavone. Investigation of the effect of upstream airways impedance on regeneration of lip oscillations in trombone performance. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811064⟩