We in the post-production audio world know that dialogue – and more specifically, performance – is king. The take where the actress nailed the line, getting just the right amount of authority balanced with feminine charm, is the one the director NEEDS to use. It doesn’t matter that there’s a plane, or bus, or gale force wind in the background. It’s our job as audio engineers to make it work. Sometimes we use an alternate take. Sometimes, the actress reproduces her lines perfectly in ADR. But many times we need to find another way.
Dialogue denoising has traditionally been done with tools that learn a selection of background noise by itself, then use this information to remove this noise from the entire file. This works well for constant, unchanging noise, but not for variable noise like those examples listed above. The quality, frequency, and volume of these noises is always changing, so it’s impossible to learn a piece of noise that will match for the entirety of the clip.
But what if we attacked the problem from the opposite direction? That is, what if we could somehow identify the speech instead of the noise, and maintain its quality while suppressing the noise in the background, allowing us to perform speech cleanup quickly and easily? Here’s how to do it with IDC: Instant Dialogue Cleaner.
IDC uses a deep neural network (a type of machine learning) based on thousands of speech files, to identify dialogue in a scene in real-time and separate it from the background content. Simply add IDC as an effect on your track (you can also use it as an AudioSuite plug-in in Pro Tools). Hit play and then turn the background knob to the left to lower the volume. You will hear your dialogue stay remarkably intact, even as challenging background noise is removed!
IDC offers up to 24 dB of noise reduction, and the same amount of control over the level of the speech. You can typically turn the background noise down significantly without affecting the quality of the speech. If you’d like to get more noise out, try increasing the strength parameter.
There are many weapons for dialogue editing and speech cleanup. IDC will make a valuable addition to your arsenal, allowing you to be the hero and save that take!