Speech Enhancement System Based On Adaptive Noise Cancellation

As one of the most commonly used tools for speech signal processing,the microphone array is widely used in video conferencing,voice control system,ntelligent voice and other fields.By using the spatial information of the sound source,the microphone array can be utilized to suppress the noise and enhance the speech signal.The noise in the whole paper refers to spatial directional noise or interference unless otherwise specified.However,the existing microphone array speech enhancement methods usually output a relatively pure speech signal without suppressing noise in specific area,which may affect our work and life seriously.This paper designs a speech enhancement system based on the adaptive noise control technique to avioding the bad influence of noise on our life.The goal of our system is to improve the output signal to noise ratio of the microphone array through performing active spatial noise control.This paper mainly completed the following aspects of the work:Aiming at the problem that the noise is seriously polluting the speech signal.The speech enhancement system designed in this paper is used to suppress the noise and realize the speech enhancement through the active noise control method.When the noise is not related to the sound source,the system can output the pure speech signal primely and form the local region without noise in the space.The accurate direction estimation of sound source is the foundation of the system in this paper.The SRP-PHAT algorithm needs global search that causes a large amount of computation.In order to solve that problem,the algorithm is improved by combining the angle pre-estimation and the frequency division search.The simulation results show that the improved algorithm effectively reduces the computational cost.And when the ambient noise is low,the improved algorithm significantly improves the direction estimation accuracy.The main advantages of this system are as follows:1.Compared with the traditional active noise control system,the system improves the dryto-signal ratio in the reference input,reduces the loss of the useful sound source,and achieves better voice fidelity.2.Compared with the traditional speech enhancement system,the system uses the adaptive noise control method to suppress the spatial noise.When the pure speech signal is output,the local area without noise can be formed in the space.3.For the case of strong noise or strong interference,the system suppresses the spatial noise interference and takes into account the speech enhancement.This system provides a new idea for suppressing spatial noise and realizing speech enhancement.