the current mute duration the serial number of the current frame u2212 the serial number of a frame corresponding to the first frame of the non mute data before the current frame the length of one frame for example in the cast that the m u2212 1 th frame and the m u2212 2 th frame of the audio record data are both non mute data and the m th frame to m n th frame of the audio record data are all mute data the current mute duration is the length of one frame when the m th frame of the audio record data is processed the current mute duration is the length of two frames when the m 1 th frame of the audio record data is processed the current mute duration is the length of n 1 frames when the m n th frame of the audio record data is processed furthermore in step 210 the current mute duration threshold may be the first time threshold or the second time threshold at different moments specifically the current mute duration is always the first time threshold before it is determined at step 206 that there is a frame of the audio record data whose characteristics acoustic model is the same as the acoustic model for.