Publication Date

1992

Document Type

Dissertation/Thesis

First Advisor

Kuo, Sen M. (Sen-Maw)

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Electrical Engineering

LCSH

Noise control; Electronic noise

Abstract

Active Noise Control (ANC) in three dimensional space is the basis for investigations presented in this work. In an effort to expand and broaden the applicability of active noise control, new concepts of an integrated audio / ANC system are devised and explored. The expansion of ANC to include audio capabilities allows for re-examination of tradition error-path modeling schemes. An introduction to the concept of ANC is shown through the one dimensional single channel ANC system. It is also an introductory goal to describe the adaptive algorithms necessary in ANC. Multiple channel extensions to the single channel ANC system are derived to make the transition from the simplified one dimensional system to the relatively more complicated three dimensional ANC system. Acoustical considerations are given, so that three dimensional ANC algorithms may be developed to interface successfully with their acoustical environment. Performance expectations of the three dimensional ANC system are given to complete the acoustical evaluations, and more concretely show the interdependence of algorithm development and acoustical phenomena in three dimensional enclosures. Review of error-path modeling precedes the Musical Interference Suppression (MIS) algorithm used to successfully integrate audio to the ANC system. It is further shown that the MIS process provides new opportunities to off-line, or partial on-line model the time varying error-paths. The evolution to a full digital ANC / audio system allows migration to digital audio signal processing, whereby system hardware resources are fully shared to accommodate both facets of the integrated system. Several digital audio signal processing algorithms are developed; the most relevant to this thesis is adaptive inverse equalization. Multiple point adaptive equalization uses a similar algorithm structure as the multi-channel ANC system. This new audio processing technique is very sophisticated by audio standards, but is a familiar re-application of the multiple error LMS algorithm derived for three dimensional active noise control.

Comments

Includes bibliographical references (pages 153-155)

Extent

xi, 162 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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