How to understand, measure, and even out the sound in your video project.
Inconsistent audio levels present challenges – both for the video-maker in post-production, and for the viewer watching (or, more specifically, the listener hearing) the end product. Here’s a quick look at sound versus hearing, followed by techniques for, and the thinking behind, managing loudness in your audio.
1. How we hear
In under 8 minutes, Tom Scott breaks down the science of sound versus the neuroscience of hearing (and, along the way, the audio regulations of platforms like YouTube and Spotify):
2. Volume vs Loudness
Curtis Judd first explains the difference between Volume and Loudness:
Some takeaways from this initial explanation:
- Volume is what the viewer / listener can adjust, while Loudness is the amount of sound available for that adjustment
- Loudness comprises:
- Amplitude – the height of the peak in a waveform
- Sustain – how long a waveform at a certain amplitude lasts over time
- Loudness can be measured by:
- dB RMS – more technically correct, but less useful; an average of amplitude over time (including silence or gaps in sound, which compromises accuracy)
- LUFS or LKFS – measures Perceived Loudness, or the way we as humans hear; a more useful metric (which doesn’t include stretches of silence in its averaging)

- Television broadcast has standard loudness limits or “targets”:
- EU: -23 LUFS
- US: -24 LKFS
- Online streaming has no unified standard:
- YouTube and Spotify: -14 LUFS
3. Loudness Normalize
With Loudness defined, Curtis then explains the concept of how to normalize, or create consistency throughout, the loudness of your audio:
Further Viewing
As demonstrated, loudness is best managed after you’ve mixed your audio:
Here are some more advanced tips for mixing audio for video: