The Merriam-Webster dictionary describes voice over as happening in two ways. Possibly It is the sound of an unseen narrator speaking, or it is the sound of a visible character expressing unspoken ideas. Creators normally pre-document the voice for later use in the motion picture. As to the asynchronous Trade, https://emiliocigwr.blogdeazar.com/29972349/5-simple-techniques-for-off-stage-commentary