In addition, because ViaVoice operates in 'near real time,' the lip sync can be done in near real time, opening many opportunities for real-time animation. Because ViaVoice provides an accurate acoustic model, the lip sync will also be accurate. Currently, lip sync for animation is often done manually, and, when it is done automatically, it cannot be done in real time and the results are not accurate. Lip synchronization ('lip sync') is the process of synchronizing a character's mouth movements with his speech.