Modeling Vocal-tract Influence in Reed Wind Instruments

This paper explores the influence of upstream vocal tract resonances in reed wind instrument performance and modeling. Vocal tract manipulations are a common, though sometimes subtle, performance practice exploited by experienced musicians to produce a variety of important acoustic effects, including contemporary performance techniques such as multiphonics and extended range playing. Several previous acoustic studies have been conducted and most agree that the upstream system can have significant influence under certain circumstances. There is less agreement regarding the importance of this mechanism in “traditional” playing ranges and conditions. Several digital waveguide structures are proposed to implement this element of the performer-instrument system. The simplest approach involves modeling the oral cavity with a single resonance peak which can be easily controlled to test coupling and reed entrainment, as well as upstream-downstream interactions. The model verifies upstream influence and demonstrates real-time behavior very similar to that experienced in reed wind instrument playing. Multi-resonance vocal tract models are briefly considered and issues of real-time control are discussed.