Lip sync

Lip sync or lip synch (short for lip synchronization) is a technical term for matching a speaking or singing person's lip movements with sung or spoken vocals.

An audio engineer (foreground) recording a voice actor (at microphone) for an animated video production. Lip synchronization of this recording with animation will give the impression that an animated character is speaking.

Audio for lip syncing is generated through the sound reinforcement system in a live performance or via television, computer, cinema speakers, or other forms of audio output. The term can refer to any of a number of different techniques and processes, in the context of live performances and audiovisual recordings.

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. Many video games make extensive use of lip-synched sound files to create an immersive environment in which on-screen characters appear to be speaking. In the music industry, lip-synching is used by singers for music videos, television and film appearances and some types of live performances. Lip-synching by singers can be controversial to fans attending concert performances who expect to view a live performance.