I am editing an instructional video of me talking. I wish to insert a graphic (such as colorboard with writing)into a portion of the video without disrupting the native sound. I have been unable to manipulate the video without doing the same splits and cuts to the native sound. I suppose what I need to do is edit video and native sound separately. Does anyone have suggestions on how to do this, or any way to add graphics into a section of video and leave the sound intact? Thanks.