Basic Study on Active Acoustic Shielding : Phase 2 Noise Reducing Performance for a Small Open Window

摘要

Active acoustic shielding (AAS) is a system that can attenuate the sound passing through an open window. The AAS system is constructed from many AAS cells set in an array each with an approximately colocated microphone and speaker. Each AAS cell is individually controlled by a single-channel feedforward method. The concept of AAS was proposed by the authors and its feasibility was proved by some simple simulations and experiments in our previous report. In this paper, an AAS window which has four AAS cells in a small open window was fabricated and installed at the door of a test room. Noise-reducing performances were measured for noise from outside the door. The effects of multiple noise sources, moving noise sources and reflected sound in the room on noise-reducing performance were also examined.