How to clean up audio: the order of operations that actually works

Cleaning dialogue is a sequence, not a preset. Each step changes what the next one hears, so doing them out of order makes every following decision worse. Here is the order used in dialogue editing rooms.

Step 0: check the file before you process

Confirm sample rate, bit depth and channel layout first. A file that is already clipped, already resampled or accidentally summed to mono cannot be repaired by a denoiser. Inspect it, and if there is a cleaner original, go back to it.

Step 1: choose the best source

If you have a boom and a lav, pick per line rather than per scene. Cleaning a good lav is faster than rescuing a bad boom, and mixing between them mid sentence is normal practice.

Step 2: remove impulsive faults

Clicks, mouth noises, clothing rustle, a chair creak. These are surgical edits. Do them before broadband noise reduction, because a denoiser will smear a click into a longer artefact.

Step 3: hum and tonal noise

Fridge hum, lighting buzz, air conditioning tone. Narrow notches at the fundamental and its harmonics remove far more than a broadband tool would, at a fraction of the damage.

Step 4: broadband noise, gently

Take a noise profile from a clean pause, then use less reduction than you think you need. Six decibels of reduction that sounds natural beats eighteen that turns the voice into a phone call. Fill the remaining hiss with room tone rather than removing it entirely.

Step 5: tone and level

Now shape. High pass around 80 Hz on dialogue, cut boxiness in the low mids if the room was small, de-ess if the lav sits close to the chin, then set level to your delivery target.

• Never denoise before you edit out clicks.
• Notch tonal noise before touching broadband tools.
• Keep a bed of room tone so silence does not sound dead.
• Compare against the untreated take regularly at matched loudness.