Ambulance Siren Noise Reduction Using Active NOISE Control System with FXLMS

Acoustic noise problems have become major issue in present technical era due to increased growth of machines, transport equipments and industrial apparatus, high speed wind buffeting and many other noise sources. Active noise control (ANC) is a particular cancelling system, based on superimposition principle, that is, a conflicting noise with equal amplitude but converse phase is produced by secondary source to nullifying the undesirable noise acoustically. In last few decades, several adaptive algorithms are developed for nullification of noise. Here we use some specific algorithm like filtered-x least mean square (FxLMS) algorithm in ANC system in which secondary sources are interlinked via some electronic system. High level noise is dangerous for human life but it is more exasperating for patients specially. In this paper, ANC system based on filtered-x least mean square algorithm is applied to ambulance siren noise. The simulations performed on MATLAB show that noise level is reduced by approximately 36-38 dB, which is a substantial reduction in level of noise. Simulations results show its effectiveness and robustness.