An analytical and experimental demonstration of a self-sensing actuato
r that is used actively to control sound transmission/radiation throug
h a vibrating plate is presented in this paper. Self-sensing is a nove
l application of piezomaterials, in which the same piece of piezomater
ial is used as both a sensor and actuator. A plane acoustic wave incid
ent on a clamped, thin circular plate was used as a noise source, and
a self-sensing actuator bonded to the plate was used to control and se
nse vibration of the plate. The sound transmission reduction problem w
as approached as a structural vibration control problem that minimizes
the velocity of the plate since the far-field sound pressure is relat
ed to the vibrating velocity of the structure. The results show that t
he first structural vibration mode is well controlled with a reduction
of at least 78 percent in the displacement and velocity of the plate.
This corresponds to a 13 dB reduction in the acoustic response. These
results indicate that it self-sensing actuator bonded to the plate ca
n be employed to attenuate the sound transmitted or radiated from the
plate. (C) 1995 Academic Press Limited