Phase mapping and sound radiation from Caribbean steelpans
Andrew C. Morrison · The Journal of the Acoustical Society of America · 2005
The Caribbean steelpan is one of the most interesting acoustic musical instruments invented in the last century. Although simple in design, the acoustic properties of the steelpan are surprisingly complicated. Holographic interferometry was used to determine the resonances of a low tenor steelpan. Placement of a vibrating mirror in the optical path of the reference beam expands the capabilities of the holography system to include phase measurements. Phase maps of several low resonances of notes on a Caribbean steelpan will be shown. Sound intensity measurements were taken to explore the relationship between the resonances and the radiated sound field. The pan was placed in an anechoic chamber, and selected notes were excited electromagnetically with a swept sinusoid signal. A two-microphone probe was used to gather sound intensity measurements. Sound intensity maps of the first three harmonics will be shown for several notes.