A 0 and A 1 Studies on the Violin Using CO 2 , He , and Air / Helium Mixtures

A determination of the A0 and A1 cavity modes (here called collectively ”air modes”) in the violin has been made using CO2, helium and air/helium mixtures. The use of a “glove bag” enabled the atmosphere surrounding the violin to be better controlled than relying on the difference in density to displace the air inside the instrument. The cavity modes in CO2 and He were moved to frequencies as predicted by theoretical considerations. A single resonance peak for A0 in CO2 and air became a doublet in He and more complex in air/He mixtures. The A1 peak was not influenced as much as A0 and remained single under all conditions. These observations were interpreted as interactions between cavity resonances, with mode frequencies determined by the current gas mixture, and body resonances.