Generalized acoustic energy density based active noise control in single frequency diffuse sound fields

Abstract

In a diffuse sound field, prior research has established that a secondary source can theoretically achieve perfect cancellation at an error microphone in the far field of the secondary source. However, the sound pressure level is generally only reduced in a small zone around the error sensor, and at a distance half of a wavelength away from the error sensor, the averaged sound pressure level will be increased by more than 10 dB. Recently an acoustic energy quantity, referred to as the generalized acoustic energy density (GED), has been introduced. The GED is obtained by using a weighting factor in the formulation of total acoustic energy density. Different values of the weighting factor can be chosen for different applications. When minimizing the GED at the error sensor, one can adjust the weighting factor to increase the spatial extent of the "quiet zone" and to achieve a desired balance between the degree of attenuation in the quiet zone and the total energy added into the sound field.

Active Noise Control Over Space: A Wave Domain Approach

“…By utilizing the acoustic energy density sensors [18], Parkins captured more global information in the enclosure and minimized the acoustic energy density (AED) [19]. Similar methods have been proposed such as minimizing the acoustic potential energy (APE) [20], and minimizing the generalized acoustic energy density (GED) [21]. Montazeri described the acoustic potential energy in terms of room modes, which depends greatly on the room geometry [22].…”

Research on follow-up active noise control with phased-array secondary sound source

“…The noise reduction mainly relies on local mutual interference effects. The noise reduction area is usually small, the noise reduction may cause noise increase in irrelevant area (Aslan and Paurobally, 2018; Brooks et al, 2005; Elliott, 2014; Olson & May, 1953; Xu and Sommerfeldt, 2014). When the control direction is no longer on the axis of the secondary sound source, the noise reduction effect deteriorates with the increase of the angle between the control direction and the axis (Furuhashi et al, 2018; Zhen et al, 2013; Iwai et al, 2018; Zhang and Li, 2019).…”

Performance of a multichannel active sound radiation control system near a reflecting surface

“…The above-mentioned papers use the total sound radiation power as the cost function, and the objective was to understand the effects of reflecting surfaces on the performance of ANC systems for global sound radiation control. There are also several papers investigating the effects of the reflecting surfaces on the performance of local ANC systems, where the main objective is to understand the variation of the quiet zone geometry rather than the total sound radiation power with control [11][12][13][14][15].…”