Lately it seems I have had to explain the process of audio post production to several film-makers. So here is a basic overview audio post production process.
Audio post production refers to the entire process of creating, fixing and finishing the entire audio soundtrack for film or television after it has been filmed or recorded.
There are several individual areas within the entire audio post process. They are:
Dialog Editing: this involves selecting the proper tracks and takes from the recorded production sound and cleaning it or removing extraneous noise, making sure it is in sync with the picture, smoothing out edits and filling in ambience gaps. Any lines that need to be replaced for technical reasons will be noted during this process as well. Once any ADR has been recorded the dialog editor will check for sync on all new lines. The dialog editor performs these tasks.
ADR or Automated Dialogue Replacement (also known as looping): When production audio is too noisy, poorly recorded or lines need to be added for story enhancement, the actors will record such lines during an ADR or automated dialog replacement session. The picture will be played back with a series of 3 beeps counting down to the required line. Where the start of the fourth beep would be, the actor will say the line to replace the production sound problem line. This is recorded by the ADR recorder and ADR mixer.
Sound Effects Editing: sound effects editors add sounds to enhance the production sound. These are broken down into background or ambience sounds(room tones, traffic noise, forests, etc.) and hard effects(gunshots, glass breaking, door opens and closes, etc.). The sound effects editors will use a sound effects library and field recordings to create sounds.
Sound Design: sound design is a term used for sounds that are not normally heard in reality and that create moods. These can be very close to music sometimes when it involves air, pads and some tones but can be as distinct as sounds for aliens, monsters and futuristic sounds.
Foley: foley is named for the man who is credited with creating the process, Jack Foley. Foley is the art of creating all human associated sounds in the movie and fall into 3 categories:
footsteps- these are created by foley walkers who create all the footsteps for all the characters in a film. They are recorded in pits in a studio. Each pit contains a different surface such as gravel, cement, marble, lino, etc.
prop sounds – these are the sounds the people make with props such as gun movements (loading, unloading), glass pick ups and set downs, body grabs, punches, etc.
movement sounds- every time a human moves, their clothes or skin makes a sound. So every pant whoosh, shirt rub, hand clasp, etc is recorded to match picture motions.
Music: music for film and television has 3 categories:
score or underscore-this is original music written by the composer to fit with specific picture.
source – music is music that is from a source in the picture, for example, a television playing on screen or a radio. Source music can be created by the composer or can be licensed from a library or band.
soundtrack -existing songs that play like score for a dramatic impact or during credit role to add to soundtrack material.
All the music will be assembled by the music editor who works with the composer to edit and make sure all the music works in sync with the final picture.
Mixing (or Dubbing): The re-recording mixer balances the levels of all the edited elements delivered to the final mix: dialog/ADR-foley / sound effects and music. Mixing is done by one person (which is more common in New York or smaller budget films) or 2-3 person teams, which is commonly seen on large budget Hollywood films. During the mix, effects such as reverb and delay are added to some elements and levels are smoothed out and balanced with faders. Equalization is used at this stage to help fix sound problems and make all the elements work as one to create a smooth and unified soundtrack for the picture.
Once the mix is done and approved, all the layers are combined to either a stereo (2 tracks: left & right) or surround (5 to 10 tracks: left/center/right/left surround/right surround) and laid off to a printmaster. This will be the final optical or digital soundtrack which syncs to the final picture for the film’s release print. In television the equivalent of a printmaster is the layback, where the soundtrack is married to the final edited master video for delivery and broadcast.