: High-definition video can sometimes lag so much that the audio drops out during preview. Try lowering the Preview Quality in the settings menu for a smoother (and audible) playback.
A common "useful story" for AVS users often starts with a frantic check of the speakers, only to find the problem is tucked away in the software's unique timeline or settings. Avs video editor no sound
If you've tried these and it's still silent, does the sound the video, or is it missing while you're still editing in the preview window? Audio - AVS4YOU >> Online Help : High-definition video can sometimes lag so much