ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

2pSA8. One-dimensional sound field control by sound pressure and energy-density sensor.

J. Warner Soditus

Jiri Tichy

Graduate Program in Acoustics, Penn State Univ., P.O. Box 30, State College, PA 16804

The use of an energy density error quantity for adaptive filtered-x active noise control has been demonstrated to provide advantages over pressure squared control in a one-dimensional experiment [S. D. Sommerfeldt and P. J. Nashif, ``An Adaptive Filtered-X Algorithm for Energy-Based Active Control,'' J. Acoust. Soc. Am. 96, 300--306 (1994)]. The performance of energy-density-based control was further explored in comparison to pressure-squared control. By using two small microphones, the pressure and energy-density sensor was moved through regions of the upstream and downstream of the secondary source in a one-dimensional low-frequency harmonic sound field. Extensive data were collected for various sensor locations to demonstrate that the pressure-based control strongly depends on sensor location, while the energy-density-based control is more sensor location-independent.