The invention relates to a method and a device for
voice activity detection. The method comprises the steps of extracting the
signal characteristics of clean voice signals and the
signal characteristics of
noise mixed voice signals, carrying out dictionary training according to the
signal characteristics of the clean voice signals to obtain a voice dictionary, dynamically updating predetermined
noise training data according to the signal characteristics of the
noise mixed voice signals, extracting the signal characteristics of the updated noise training data and carrying out
online dictionary training to obtain a noise dictionary; performing sparse representation on the signal frames of a noise mixed voice signal input according to the voice dictionary and the noise dictionary, extracting a
sparse coefficient in the sparse representation, and detecting the signal frames of the input noise mixed voice signal according to the
sparse coefficient. The method and the device are capable of accurately recognizing the voice part and the non-voice part of a voice signal in a noise environment, and the performance of the
voice activity detection in the varying noise environment is improved.