Method and system for dereverberation based on Kalman filtering

Abstract

The present invention discloses a method and a system for dereverberation based on Kalman filtering. The method comprises the steps of: performing preprocessing of original signals collected by each microphone to obtain corresponding frequency domain signals, and forming input signals after delay; employing the Kalman filtering algorithm and a time-varying multichannel autoregressive model to estimate reverberation signals, taking the original signals collected by each microphone at the current moment as reference signals, and subtracting the reverberation signals from the reference signals toobtain error signals; employing a Kalman gain matrix and error signals to update a Kalman filter coefficient; employing the original signals collected by each microphone at the current moment, the input signals and the updated Kalman filter coefficient to obtain target signals; and finally, employing inverse Fourier transform to convert frequency domain object signals to time domain object signals. The method performs diagonalization of a Kalman filter state vector error covariance matrix to reduce the complexity of the adaptive multi-channel linear prediction dereverberation algorithm.

Description

technical field [0001] The invention relates to the field of speech reverberation, in particular to a method and system for reverberation based on Kalman filtering. Background technique [0002] Such as figure 1 As shown, due to the reflection of sound waves by room boundaries and objects in the room, the microphone receives reflected sounds from all directions in addition to the direct sound from the sound source. Generally, the sound signal arriving 30-50 ms after the direct sound is called the early reflection sound, and the sound signal arriving after that is called the late reflection sound, that is, the reverberation tail. Psychoacoustic research has found that early reflections can enhance the intensity of direct sound and improve speech intelligibility. The reverberation signal will mask the subsequent arrival of the direct sound signal, resulting in blurred speech. In addition, the reverberation signal will also reduce the voice quality of the signal received by ...

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