Lip Sync
Matching a speaker's mouth movements to the audio so the words look naturally spoken on camera.
Definition
Lip sync (lip synchronization) is the alignment of a person's — or an avatar's — mouth movements with the spoken audio. When it's accurate, the speech looks natural; when it's off, the mismatch is immediately noticeable and breaks the illusion that the person is really talking.
Why it matters
For talking-head and spokesperson video, believable lip sync is essential. Poor sync is one of the fastest ways to make a video feel artificial, which undermines the authentic feel that UGC-style ads depend on.
How it applies to UGC ads
AI avatar tools generate lip movement to match your script's voiceover, and the quality of that sync is a big part of how realistic the result looks. It also makes localization easier — the same avatar can be synced to a script in another language.
Related terms
AI Avatar
A computer-generated digital presenter that can speak a script on camera, used to create video content without filming a real person.
ReadFaceless UGC
User-generated-style content that never shows a presenter's face, relying instead on hands, product shots, voiceover, and text.
ReadUGC Ad
A paid advertisement made in the casual, authentic style of user-generated content rather than as a polished brand commercial.
ReadB-Roll
Supplemental footage cut in over the main shot to illustrate what's being said and add visual variety.
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