Ambulance siren noise reduction using psychoacoustic active noise control system with A-weighting filter

Acoustic noise is present everywhere and often affects our lives, but it is more troublesome to the patients. When the patient in serious condition is being taken to the hospital in an ambulance, he has to cope with continuous noise of siren. The patient feels annoyed and this can further deteriorate his health condition. Active noise control (ANC) system is employed to conquer the unwanted noise. But conventional ANC system intends to reduce the residual energy of noise, which cannot be discriminated in the frequency domain, while the human perception of sound is frequency dependent. A-weighting filter approximately model the frequency response of human hearing. In this paper, ANC with A-weighting filter (called Psychoacoustic ANC) is applied to the ambulance siren noise. The simulations are performed in MATLAB and results show that noise level is reduced by 62 dB, which is a considerable reduction in noise level.