Removal of Siren Mixed With Speech by Wavelet Tranform and Adaptive Notch Filter

Siren signals are used to warn other cars and pedestrians about the presence of an emergency vehicle. This signal is leaked into the communication path between the emergency vehicle and the emergency call centre and substantially degrades the intelligibility of the speech signal. In the past, research has been mainly focused on siren cancellation on the source of siren signal by using an extra microphone which requires consideration of acoustical characteristics of the emergency vehicle. The solution and approach in this paper is for attenuation of the siren in the emergency call centre without having any knowledge about the emergency vehicle, type of siren and the presence of a siren.