Modeling local active sound control with remote sensors in spatially random pressure fields

Area of Science:

• Acoustics
• Signal Processing
• Control Theory

Background:

• Active sound control aims to reduce noise in specific regions.
• Existing methods often require sources and sensors to be in close proximity.
• Controlling sound fields generated by spatially random primary fields presents unique challenges.

Purpose of the Study:

• To develop a general formulation for an optimal controller in active sound control systems.
• To enable selective sound attenuation in a control region using remote secondary sources and reference sensors.
• To analyze the controller's performance under various primary field conditions.

Main Methods:

• Formulation of an optimal controller combining least-squares estimation and a least-squares controller.
• Application of the remote microphone technique in both frequency and time domains.
• Modeling of stationary sound fields using a spectral density matrix for primary sources.

Main Results:

• The optimal controller effectively attenuates sound in the control region.
• The controller's structure is determined by the estimation of primary source signals and subsequent control.
• The spatial characteristics of the primary field significantly influence the resulting zone of quiet.

Conclusions:

• A robust framework for optimal active sound control in complex sound fields is established.
• The proposed controller offers flexibility in managing sound fields generated by various source configurations.
• This research provides a foundation for designing more effective local sound control systems.