Abstract:
Planar near-field acoustic holography gives one the ability to reconstruct the sound pressure radiated from a source in a three-dimensional field from a single two-dimensional near-field measurement. Traditionally, only one measurement plane has been used which gives the sound radiation in a half-space. In this paper, the near-field acoustic holography is modified to measurements taken on six planes configured as a ``box'' surrounding the source, thereby giving the sound radiation in all directions. Any source may then be put into this ``box''; in this case, a violin is used as the source from which sound radiation patterns can be determined. Preliminary simulations using the modified near-field acoustic holography with six planes are presented. Also, methods of violin excitation with a bowing machine and the positioning of the violin within a measurement frame are described. It is expected that many violins may be tested with this setup, therefore providing a tool for assessing the effects of different modifications to violins on sound radiation. [Work supported by NSF and an AT&T GRPW Grant.]