A feedforward and feedback composite active noise reduction headset based on inverse filter frequency equalization and its DSP system implementation

Abstract

The principle of active noise reduction headset is to reduce the original noise by generating inverted noise through the loudspeaker. The loudspeaker system will introduce spectrum distortion inevitably. This distortion will increase the complexity of the secondary channel model, which adversely affect identification of the primary channel in the real-time active noise reduction system. To improve the inherent frequency spectrum distortion of the speaker system, this paper proposes a new frequency equalization method based on inverse filtering. This method is applied to a feedforward and feedback compound active noise reduction earphone system, and a new active noise reduction headphone system is obtained. In order to improve the noise reduction effect, the pollution caused by the secondary sound source to the reference signal is compensated in the active noise reduction control scheme of this paper. Simulation and real-time noise reduction experiments based on DSP solution show that this new active noise reduction control system can achieve better noise reduction effects.