What if I told you that the most important aspect of a video is not the visuals? It’s actually the audio editing that can make or break a video. Don’t believe me? Think of every movie you’ve seen in the last decade where you or someone you know complained about inaudible dialogue, music that was too loud, and jarring shifts in volume from one scene to another. Think about how it would feel to watch a vlog filmed on a cinema camera but with muffled dialogue, versus a vlog filmed on an old and cheap camera but with crisp and clear voices.
The point is that audio is incredibly important. It can be essential to understanding what is happening in a piece of media, and it can be frustrating or even unpleasant if the audio is off. It’s why every podcast seems to use the Shure SM7B – because it’s a microphone that has a high baseline for sound quality and can make even the most boring podcast at least sound professional.
Good audio editing in video is not just about using a nice microphone and boosting the volume. There is an art to it that will make your videos more enjoyable to watch, and these are six tips to improve your own.
1. Use a Variety of References
You may be happy with how a video is sounding, only for your friend or colleague to say it sounds terrible on their setup. How is that possible? It sounds great to you. Well, that’s exactly the problem. If you’ve only used one pair of headphones or one set of speakers to edit your audio, then you’ve perfected the sound for that hardware, but ignored all other hardware. Export your audio track, then listen to it on every pair of headphones and every speaker you can find.
Listen to it on a laptop, on phone speakers, and in your car. Ideally, it should sound good on the lowest common denominator (this will usually be phone or laptop speakers, for better or for worse). Keep in mind who your audience is, and that they won’t all be using expensive headphones to listen to your video.
2. Be Mindful of Volume Mixing
When you have music, sound effects, and voices in a single scene, it can be challenging to mix them appropriately. In an ideal world, each sound should be identifiable in a scene. But sometimes you will need to prioritize the dialogue and make it stand out from the music. The simplest way to achieve this is to duck two tracks against each other. This means that when one audio track is producing audio, it dynamically lowers the volume of another track. It’s common to use this technique to lower the volume of the background music while speakers are talking, then raising it again when they’re not.
You can also delve into the equalizer tool to separate the frequencies of your different audio tracks. When two audio tracks are fighting for the same frequency range, they can get muddled and neither will be clear. So, once you identify what range your speakers occupy (perhaps by visually looking at an audio waveform on an equalizer), you can drop the volume on that same range of your music track. With this simple trick, you can make your audio tracks stand out from each other.
3. Fade Your Audio Tracks
Every single audio track should have a very short fade-in and fade-out. And by short, I mean a few milliseconds. When you listen back to your audio track, you probably won’t be able to hear the difference. But, many audio tracks contain some level of noise. This noise becomes obvious when it abruptly gets cut off, and a short fade can help mask this.
A harsh cut on an audio track can also result in popping or clicking when the audio track ends and a super short fade can mitigate this annoying sound. This may sound tedious, but don’t worry. Most video and audio editing programs should have a way to mass-apply an effect to a selection of clips. So you can wait until the end of a project to apply your fades, and bask in the glory of professional audio.
4. Clean Up Your Audio Like a Pro
While some audio tracks simply can’t be saved, a professional editor should be able to make the most out of a bad take, if that’s all they have to work with. Although, it should be said that if possible, you should request a version recorded in ideal conditions. Luckily, audio and video editing programs come with a ton of presets for mitigating background noise, reverb, and sharp sibilance.
If your audio tracks contain background noise like a fan or other consistent sound, you can run a denoise filter over it and lose very little of the sound you intend to keep. Dereverb effects can also do a lot to save an audio recording, but it’s also easy to ruin your audio this way. A de-esser will help get rid of sharp syllables like “s” that might make it sound like you’re being stabbed in the ears when your subject talks.
It’s up to you as the editor to find the balance between noise reduction and audio clarity, but there are tools out there that you shouldn’t ignore.
Compression is a basic but incredibly important step in the audio editing process. Human speech can often have a wide volume range between quiet and loud parts, and these differences are much more apparent on a recording.
A compressor aims to reduce the difference in volume between these quiet and loud portions, and produce a vocal track that is more consistent. The “compression” refers to the fact that the audio waveform is being pressed together to remove peaks and valleys, then gain is applied to the whole track to make the correct volume again.
6. Use Precise Editing
A professional dialogue track is one that is free of “um”s, “ah”s, long pauses, and breaths. It requires an attentive ear to catch all of these, but their presence makes for a more annoying listen. Removing pauses will keep the video flowing at a reasonable pace. There is an old video editing technique put into words by editor Walter Murch of making a cut right before an actor blinks so that you never actually see the blink, but the audience gets the same effect thanks to the scene change and the emotional expectation that there should be a blink.
You can apply the same logic to cutting out things like inhales and exhales from an audio track. In the video, these cuts can be masked by changing the camera angle or inserting B-roll shots over the cuts. This technique goes hand-in-hand with the video aspect of the edit, as you can use video to cover up the audio edits. Most of the time, the breath will be implied by the cut, or the viewer won’t even realize the speaker needed to take a breath at all.