Vasundara V. Varadan
Vijay K. Varadan
Dept. of Eng. Sci. and Mech., Penn State Univ., University Park, PA 16802
The performance of active sound isolation by using a piezoelectric sensor and an actuator on a thin plate is investigated experimentally. In the experiment, the aluminum plate covers an opening of an acoustic enclosure, where a sound source is located. The outside acoustic field is measured by an 11-element microphone array, which scans on a surface of a hemisphere. The isolation performance of the original plate is poor at its resonance frequencies. The sound transmission from inside to outside of the enclosure is actively controlled by a one-sensor one-actuator control system which minimizes the output of the on-plate sensor. Global reductions of 15--20 dB are achieved at the first three resonance frequencies.