Experimental research on vibrating objects and its radiation field using near-field acoustic holography

This paper presents the Near-field Acoustic Holography (NAH) imaging system for airborne sound constructed in our own laboratory. Using the system we have measured the vibrating modes and the radiated fields of a single loudspeaker, duplex loudspeakers and a unbaftled disc, and gotten interesting results. These results tally with theoretical analysis and computer simulations, and indicate that NAH can be used to research the relation between the vibrating mode and its radiation field as an effective means.