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Volume 121, Issue 6, June 2007
- MUSIC AND MUSICAL INSTRUMENTS 
121(2007); http://dx.doi.org/10.1121/1.2722238View Description Hide Description
The violin radiates either from dual ports ( -holes) or via surface motion of the corpus , with no clear delineation between these sources. Combining “patch” near-field acoustical holography over just the -hole region of a violin with far-field radiativity measurements over a sphere, it was possible to separate -hole from surface motion contributions to the total radiation of the corpus below . A0, the Helmholtz-like lowest cavity resonance, radiated essentially entirely through the -holes as expected while , the first longitudinal cavity mode with a node at the -holes, had no significant -hole radiation. The observed radiation comes from an indirect radiation mechanism, induced corpus motion approximately mirroring the cavity pressure profile seen for violinlike bowed string instruments across a wide range of sizes. The first estimates of the fraction of radiation from the -holes indicate that some low frequency corpus modes thought to radiate only via surface motion (notably the first corpus bending modes) had significant radiation through the -holes, in agreement with net volume changes estimated from experimental modal analysis. generally trended lower with increasing frequency, following corpus mobility decreases. The -hole directivity (top/back radiativity ratio) was generally higher than whole-violin directivity.