title: Vibrational behavior of a soundbox in an atmosphere with a variable speed of sound.
abstract: This paper describes a semi-quantitative method, suitable for a student laboratory exercise that shows that the acoustic properties of the soundbox of a musical instrument depend on the sound speed of the atmosphere surrounding and filling the instrument. A gas tent was constructed and used to enclose instruments in helium, carbon dioxide and mixtures thereof, allowing the sound speed to be varied from 250 to 1000 m/s. Soundboard admittance data were taken using a guitar and a violin as examples. The data, expressed as contour plots, show clearly the qualitative relationship between air and wood modes, and the guitar data are compared with a simple mechanical model. Experimental details of the construction and operation of gas tent are given, with attention paid to safety issues.
authors.affiliation: Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
authors.forename: Mo
authors.initials: M
authors.lastname: Chen
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kotlicki
authors.forename: Chris
authors.initials: C
authors.lastname: Waltham
authors.forename: Nathan
authors.initials: N
authors.lastname: Wolfe
authors.forename: Jing Fei
authors.initials: JF
authors.lastname: Yu
authors.forename: Chenchong
authors.initials: C
authors.lastname: Zhu