Passive Control of Sound System of Coupled together Inner and Outer Sound Field Separated at Enclosure.

Abstract

The sound field coupled with inner and outer space separated at an enclosure has been analyzed by using the boundary element method and reported. It has been available that the most of sound energy more than 80% is flooded from the opening of the enclosure. Then, it is desired that the sound energy shall be decreased while it pass through the neck of opening of enclosure and the passive sound control system, which is consisted of the cave in the neck and the damping attached to the inside wall, is proposed for this object. The sound passing the neck of opening of enclosure is introduced to this sound control system and the most of sound is dissipated by damping material attached to the inside of the system. The effectiveness of this system is proven by computer simulation and experiment.