반사면 위에서의 컴팩트 원형 하이브리드 소음 제어 시스템

Abstract

The compact hybrid noise control system is proposed to prevent noise-induced hearing loss of workers in industrial sites. Noise in a wide frequency band can be reduced through a hybrid method combining a noise barrier, which is a passive noise reduction method, and active noise control. Unlike conventional active noise barriers that use semi-infinite barriers and error microphones, a finite-sized circular barrier is used for movability, and a control filter based on theoretically calculated sound fields is applied without error microphones for convenience of installation and calibration. However, in the prior study, simulations and experiments were conducted under free field conditions. Because free field conditions are acceptable only in specific spaces, the verification of the compact hybrid noise control system on the ground is required for practical use. Therefore, in this study, the compact hybrid noise control system is examined on a reflecting surface. To retain the advantages of movability and simple installation, a theoretical model in the free field should be used to obtain a control filter. Nevertheless, it is shown that the noise in the target control space is reduced by approximately 6 dB in a frequency band of interest. It is also demonstrated that the noise reduction performance can be improved by suppressing the noise reflection through a sound absorbing material and active noise control.