Vibrational and Perceptual Analyses of Musical Instruments

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The long-term goal of this scientific research program is to gain a better understanding of the acoustical, fluid-dynamic and mechanical properties of musical instruments that can be applied to improve their design and manufacture. My previous Discovery Grant research has resulted in significant advancements and contributions to this long-term program, including the development of numerical and analytical methods to better characterize the acoustic behaviour of woodwind instrument air columns, player-instrument coupling and the human perception of instrument qualities. Over the next five years, we will make use of state-of-the-art measurement and computer modeling techniques, as well as perceptual studies, to help music instrument makers innovate and benefit from new technologies.     Musical instruments have been refined over centuries through empirical methods. And yet, there remain various problems experienced by makers, manufacturers and players for which solutions can or must be found. For example, certain species of wood commonly used for guitar fingerboards and violin bows are now either endangered and/or illegal to import into Canada. As well, the traditional cane reeds used on clarinets and saxophones are well known to be inconsistent and prone to rapid decay. New materials can be investigated as replacements and evaluated using vibrational measurements, modeling and perceptual studies.      The first specific component of this research program will involve macro- and micro-structural analyses of woodwind reeds, with the aim of designing durable composite reeds that perform as well as traditional ones. Reeds are graded by stiffness but there are large variations of overall stiffness within a box and it is common that a musician may find only 20-30% of them of good quality. This study will begin with an assessment of these inconsistencies by evaluating the external geometry and internal cell structures of reeds. After identifying measurable properties and finding correlations with a desired response, reproductions using composite materials will be investigated.     A second component of this research program will focus on studies of saxophone and clarinet mouthpieces using Finite Element (FEM) and lattice Boltzmann numerical methods. Small variations of mouthpiece geometry are known to have important influences on the sound and response of instruments, though no clear design strategies have yet to be developed, in part because of the complicated aeroacoustic behaviours present at the mouthpiece / reed / air column boundary. Our studies will consider the use of FEM to evaluate the acoustic characteristics of mouthpieces and numerical fluid-structure models to evaluate the aerodynamic aspects. The goal is to better understand how geometry refinements impact response so that mouthpieces can be better tailored (using computer modeling and 3D printing) for individual musicians.