Psychoacoustic active noise control system with auditory masking

In practical active noise control (ANC) applications, it is difficult to completely cancel out the undesired noise. In order to improve the user's comfort level in a noisy environment, a psychoacoustic ANC system that incorporates masking techniques is proposed in this paper. A two-stage approach of performing ANC, followed by masking the residual noise with carefully selected masking signal, is used to enhance the user's listening experience. In order to mask the residual noise effectively, an automatic gain controller (AGC) is used to give different gains to the masking signal according to the residual noise level. A new mechanism to control the gain of the AGC is proposed so that the system can produce a conclusive listening experience for the user. The proposed hybrid ANC-masking system also takes into account of any uncorrelated noise that is only captured by the error microphone. Computer simulations are conducted to show the superior performance of the proposed psychoacoustic ANC system. Two real-signal cases are also considered in this paper to test out the effectiveness in combining ANC with masking.