They use "
foley" sound. They build the soundtrack layer by layer and "construct" what you hear. It is not done in a single pass. The audio alone can take days or weeks to build. (Sometimes, they do not record original foley sounds but use canned sound effects and other bits and pieces that they grab from sound libraries.)
Each element is placed just where they want the sound to happen and at the volume, presence, etc., that works for the piece.
They also use trickery like
ADR audio, where they use the "live" audio as reference and re-record the voiceover parts using ADR -- replacing the original voice with the new ADR track.
HTH.
Best regards,
Ronald Lindeboom
CEO, Creative COW LLC
Publisher, Creative COW Magazine
A 2011 FOLIO: 40 honoree as one of the 40 most influential publishers in America
http://www.creativecow.net
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