Lip sync, lip-sync, lip-synch (short for lip synchronization) is a technical term for matching lip movements with sung or spoken vocals. The term can refer to any of a number of different techniques and processes, in the context of live performances and recordings.In the case of live concert performances, lip-synching is a commonly used shortcut, but it can be considered controversial. In film production, lip synching is often part of the post-production phase. Dubbing foreign-language films and making animated characters appear to speak both require elaborate lip-synching. Strategy video games make extensive use of lip-synced sound files to create an immersive environment.