Sound production is an equally important part of the post-production process as conventional story editing or visual effects. Sound ends up adding information and dimension to the film. It only becomes truly cinematic once all of the elements play together in a multi-layered soundtrack.
One of the first parts of your sound process is called spotting. This means that once you have begun to do your story editing you “spot” problem areas with the natural audio. This should be done in a log similar to the one you might do to keep records of the quality of specific takes or pieces of footage. From here you will know what you have to do next.
Check it Over
Go through the rest of the recorded audio and see what needs to be altered. Some may need to be cleaned up in an actual sound editing program, while others may just need their volumes altered. This is actually more standard that it may sound and will be the majority of your mixing since on set sound problems are not an anomaly, but to be expected. Most films require some form of Automated Dialogue Replacement, or ADR. This is where the voice track is dubbed over in a studio to sound as if it was filmed live. This is common because audio problems are occurring with dialogue on set and it needs to be captured clean. On most sets you can expect something like twenty to thirty percent of your dialogue to be ADR’d, which requires a whole other level of audio mixing.
Beyond this you are going to have to adjust for any problems with interference in the microphones and for the actual construct of the sound areas you are in. Unless you are in a studio sound stage it is next to impossible to cut out all outside environmental sounds such as passing cars or planes, distant people, or, the most difficult, wind. This will require you to utilize the room tone that you captured when you were filming, cut out problem areas as much as possible, and create continuity by bridging together the clips. If there is too much background noise then you will need to do more ADR to have clean dialogue that you can then add to make it sound as if it was actually recorded in your environment.
From here you should begin to put in your pre-lay sound effects. These are sound effects that have already been recorded, either by you or by someone else, that were contained in anticipation of their use. This means that you already knew that you were going to need them so you just go ahead and put them in at specific points. This is also where you would record any effects that you do need and put them into the project. The recording of your own effects, which is called Foley, you will need to utilize either a specific quiet space or a sound proof studio to recreate specific sounds. This works really similarly to
Once your basic sound and effects are clear you need to start laying down the musical tracks. Depending on whether you are using specific pre-recorded songs or a specially written compositional score you are going to have to arrange this in different ways. Do not let the music over power the dialogue or action sound unless that is part of your device. The music needs to always add to the project holistically and should never stand out on its own. This can be the easiest part of the audio process because it usually just involves importing music files that have already been recorded and mastered.
The Final Mix
Now you do the final cut just as you would in editing. You smooth out all the audio transitions, making sure that each small clip matches the surrounding ones in volume and clarity. Remember, you want it to all look as it is happening in one place so it needs to be as smooth as possible. In this way audio is the most important way that you will get you audience to suspend disbelief. It is important to think about the final mix as a totality where all clips need to sound as if they were recorded as one, which they never are. This is incredibly difficult and requires the use of altered audio tracks, overlapping, cutting very delicately inside of them, and so on. This can be as simple as setting fades on the beginning or end of every clip, or as complicated as integrating dozens of audio tracks so that they are indistinguishable in your sound design. Listen to your final mix with your eyes closed so that you can hear any pops or mistakes.