Production Sound
Sound recorded during filming (production). Sometimes referred to as "sync sound." The term includes any audio recorded during filming such as wild track audio or room tone.
Scratch Audio
A scratch track is an audio recording that is used as a reference for the final (or replacement) audio but is not intended to be used in the final production. For example, we may use a GoPro for recording a car chase scene, but we will replace all of the audio in post production.
Sync vs. MOS
Sync is a production sound that involves people speaking. The names come from lip-syncing. This audio is recorded on set.
M.O.S. is a video recorded without sound. M.O.S. stands for Mit Out Sound.
Additional Audio
Some other audio files that an editor might receive from the sound production team include:
Wild Track or Wild Line - A line of dialogue recorded off-camera but during production, to be edited into the scene during post-production.
Room Tone or Ambient Sound - The sounds of a location or space. Depending on how audio was recorded on set, cutting from one shot to another can sound different due to the ambience shifting. Because of this, audio is recorded at every location during production for one minute with only the natural sound of the location (all cast and crew are asked to be quiet when room tone is being recorded.) This audio track can be used by the editor to smooth out the different ambiences between cuts.
Location Sound Effects - Sometimes, a location has unique sound effects—for example, a scene recording near a waterfall or train station. During downtime, a sound recorder might walk around and record these sound effects up close to give the post-production team unique options for their final sound mix.