Post Production Sound Editing Step by Step
Post-production sound editing is where raw production audio gets shaped into the polished soundtrack an audience hears. The process doesn’t start until the picture is locked, meaning the edit is final and no clips will be added, removed, or rearranged. Working on sound before picture lock wastes hours of editing that gets thrown out when scenes change.
Once the timeline is set, the production sound mixer’s recordings become the raw material for everything that follows. From here, post-production sound editing moves through four stages: dialogue editing, sound effects, music, and the final mix. Each stage builds on the previous one, and the order matters.
WHEN TO START POST PRODUCTION AUDIO EDITING
Picture lock is the starting line. Color correction, visual effects, and titles can still be in progress, but the cut itself must be final. If scenes get rearranged after sound editing begins, every audio edit tied to those scenes has to be redone.
Before starting, the sound editor typically receives a reference mix (also called a “scratch mix”) from the picture editor, an EDL (edit decision list) or AAF/OMF export of the timeline, and all original production audio files. If the production sound was recorded using dual-system sound, the sound editor will also need to sync those files to the picture before editing begins.
UNDERSTANDING THE SOUND EDITING WORKFLOW
The post production audio editing workflow may vary slightly from one sound editor to the next, but the general rule of thumb is to execute in the following order:
- Dialogue
- Sound Effects
- Music
- Mixing it All Together
Let’s take a look at each step in closer detail.
DIALOGUE EDITING IN POST PRODUCTION
The first step of the audio editing process is to focus on the dialogue. At this phase in post production sound editing you want to remove distractions that take away from the dialogue.
The sound editor is focused on clip corrections and the proper sync of ADR as well as on the removal of any sounds that should not be present with the dialogue such as clicking of the tongue or background noise that is interrupting the dialogue.
During the dialogue editing phase, the sound editor is also focusing on EQ. Monitoring the frequencies of the dialogue sound and removing any frequencies that are unwanted from the file.
Sound editors do not add frequencies but rather focus on removing the barrier frequencies that are causing the problem with the audio.
In order to finalize the dialogue, the addition of transitions may be required. Audio transitions such as fading and bridging various audio clips together take place at this time. The goal is to have a crisp, clear dialogue track when this phase is complete. Room tone, the ambient silence recorded on set, is used to fill gaps between dialogue edits so the background sound stays consistent. Without it, cuts between lines sound jarring because each take carries slightly different ambient noise. When production dialogue is unusable (too much background noise, bad mic placement, or performance issues), the editor works with ADR recordings to replace specific lines while keeping the performance intact. Our guide on what an ADR mixer does covers the technical side of that process.
SOUND EFFECTS IN POST PRODUCTION
The next step in post production audio editing is to add in sound effects that will make the performances more realistic and engaging. Hard effects are added first. These include any single sound additions that are placed precisely where the action occurs.
The next step in the sound effects phase of sound editing is to add foley sound. Foley sound recreates the physical sounds of on-screen actions: footsteps, clothing movement, doors closing, glasses clinking. A foley artist performs these sounds in sync with the picture in a recording studio, giving the editor clean, isolated tracks for each action. Understanding how to layer these sounds effectively is what separates flat audio from immersive film sound.
Finally, time is taken to create the final ambient layer of sound. At this point, the focus on sound effects is to create the feel of the scene whether it’s calm, eerie, or something else. Ambient sound is one of the most overlooked elements in post-production. A scene set in a busy restaurant needs a specific atmosphere (clinking dishes, murmured conversation, kitchen sounds). A scene in a forest needs wind, rustling leaves, distant birds. These details are what make audiences feel physically present in the world of the film. For more on how sound design carries a film from raw edit to final delivery, see our full breakdown.
Ambient sound may be as simple as the birds chirping in the background of a typical spring day scene or a light buzzing as it flickers above in an eerie horror scene. The sounds that are typical for the background ambience are added at this point.
All of these sounds are layered in to produce the sound effects that make up the film. Dialogue is added first, then hard sound effects, followed by the additional layers of on-screen action sounds from foley and ambient sounds.
The final layer is the addition of any production related elements that add impact to graphics or titles that appear on screen.
MUSIC IN POST PRODUCTION
The addition of music comes after everything happening on the screen has already been given a dedicated sound. Audio editing in post production requires the addition of music either original or stock files depending on the budget for the film.
Sound editors will listen to sometimes hundreds of tracks before finding the perfect fit for the production. Royalty-free music libraries offer a range of tracks with alternative instrumentals, arrangement variations, and loops that can be edited to fit specific scene lengths. When using licensed music, understanding music synchronization rights is critical. Using a track without proper clearance can result in distribution holds or legal action, even if the track came from a library.
If stock music is used, it is also important to ensure that the video that the music is to be used on aligns with the project rights provided by the music provider, otherwise legal troubles related to music copyright may ensue later on. For the full scope of sound editing tools used by professionals, our overview of sound design software for film covers the most common platforms and their strengths.
MIXING IT ALL TOGETHER IN POST PRODUCTION
The final stage of post-production sound editing is the mix. The sound editor delivers separate stem files, typically three: dialogue, music, and sound effects (sometimes called the “D-M-E” stems). These are combined in a mixing session where a re-recording mixer balances levels, applies final EQ and compression, and ensures the audio translates well across different playback environments, from theater speakers to phone earbuds.
The re-recording mixer also handles panning (placing sounds in the stereo or surround field), managing dynamic range so quiet dialogue and loud explosions both work at the same volume setting, and creating alternate mixes for different delivery formats. For broadcast, a separate “M&E” (music and effects) mix is standard because it allows international distributors to replace the dialogue track with dubbed versions.
The final deliverable is a master audio file (or files) synced to the picture, ready for color-corrected video to be married to the sound in the finishing stage.
For a comparison of the two most common professional mixing tools, see our breakdown of Reaper vs. Pro Tools for film sound design.
Whether you’re editing a short film, a documentary, or a corporate video, professional sound editing is the difference between content that feels finished and content that doesn’t. Learn more about our video production services or get a free quote to discuss your project.
Forbes Business Council Member | 24+ Years in Film & Video Production
