LIPSYNC

Linking of speaker's mouth movements and voice in filmed recordings (3,4)

Solution has appeared in 2 crosswords (1 across and 1 down):

• Quick crossword No 15,737 — 2020-10-13 23:00:39
  18A: Move mouth to fit a soundtrack (3-4)
• Quick crossword No 15,197 — 2019-01-22 00:00:01
  15D: Linking of speaker's mouth movements and voice in filmed recordings (3,4)