Sound spot generation by 128-channel surrounded speaker array

This paper describes sound spot generation by 128-channel surrounded speaker array. A sound spot is a limited area within which an emitted sound is amplified. Sound spot generation is achieved by the Sum and Delay Beam Former (SDBF). A dedicated PCI 128-channel simultaneous input digital-to-analog (D/A) board is developed for a 128 channel speaker array with a maximum sampling rate of 22.7 /spl mu/s/sample. The 128-channel square speaker array can generate steerable a sound spot towards a specific point. Sound spots can be moved in approximately 10 ms. The speaker array can also generate different sound spots at specific points simultaneously. The performance of sound spot generation is evaluated by using sound pressure distribution maps. The speaker array can be used to that transmit necessary sound information to only a specific person in quiet places, such as a museum and a hospital.