Lip sync

Lip sync, lip-sync, lip-synch (short for lip synchronization) is a technical term for matching lip movements with pre-recorded sung or spoken vocals that the listeners hear through speakers, either through PA system speakers in a "live" performance or television or cinema speakers in the case of a lip-synced TV show or film performance. The term can refer to any of a number of different techniques and processes, in the context of live performances and recordings.