SOUND EDITING There are two types of Sound Editing: Sound Mixing -- This can be done in either the original shooting process or in editing. Two or more sound sources can be connected to a sound mixer and then inputted into a camcorder's external mike jack (note: not all camcorders haved an external mike jack).Two or more sound sources can be connected to a sound mixer, then inputted into the record VCR's audio input jack(s). This enables the sound to be altered or added to during the editing process. Audio Dubbing -- This is the technique of adding audio to footage that is already edited together or previously shot. The audio is added to the video tape without altering the previously recorded video and, in some cases, without altering the previously recorded audio.In order to do either of these processes, the VCR must have an Audio Dub function already built-in. In addition, in order to audio dub without affecting the previously recorded audio, the recording VCR must be a HiFi Stereo VCR with a built-in Audio Dub function.Audio Dubbing is usually activated by placing the VCR in the Play/Pause mode, then pressing the Audio Dub function, then letting the VCR play the video while it records the audio.Note: Audio Dubbing on HIFI consumer VCR's only allows for a Monural Audio Dub - useful for narration or effects. see more on editing