5aSA5. Multiple-reference adaptive active noise control in enclosures.

Session: Friday Morning, May 17

Time: 10:20

Author: Zane M. Rhea
Location: Grad. Prog. in Acoust. and Appl. Res. Lab., Penn State Univ., P. O. Box 30, State College, PA 16804
Author: Scott D. Sommerfeldt
Location: Brigham Young Univ., Provo, UT 24360
Author: Courtney B. Burroughs
Location: Penn State Univ., State College, PA 16804


Noise control of multiple noise sources in 3-D enclosures remains a concern in many applications. This is of particular interest in vehicles, where multiple primary sources contribute to the sound field inside the enclosure. When utilizing active noise control (ANC) systems in these applications, multiple reference inputs are required. A comparison of active noise control with multiple and single reference inputs of multiple noise sources is presented in a case format. Since most sources are structural in origin, independent harmonic vibration of two of the rectangular enclosure walls are used as the primary noise sources. Although a multiple reference input ANC system is much more successful at controlling multiple noise sources, care must be taken in choosing the reference inputs. If the reference inputs are not independent the ANC becomes ineffective. Also, a case study of sound-pressure reductions obtained for on and off resonance of both the enclosure and the enclosure walls is presented. [Work supported by the Applied Research Laboratory.]

from ASA 131st Meeting, Indianapolis, May 1996