unknowingly created mental pictures that appear to be records of the physical universe but are, in fact, only altered copies of the time track. The term comes from the phrase dub in in the motion-pictureindustry, meaning to record dialogue and various sounds and then integrate them into the film after it has been shot. See also track in this glossary.—HDA Tapes (Oakland Lectures) Approved Glossary (16.4.92)