2 June 2026 | 7 min read
How to remove background noise from audio without destroying the voice
Noise reduction is the last step, not the first. Here is the order that keeps dialogue sounding like a room instead of a swimming pool.
Every dialogue editor has done it: dropped a noisy take into a denoiser, pushed the slider until the hiss disappeared, and ended up with an actor who sounds like they are speaking through a fish tank. Noise reduction is not one tool, it is an order of operations.
Identify what the noise actually is
- Broadband hiss: preamp noise, wind cover self noise, a gain structure problem.
- Hum: 50 or 60 Hz mains, plus harmonics at 100, 150, 200 Hz.
- Rumble: traffic, HVAC, handling, mostly below 80 Hz.
- Intermittent noise: a fridge, a plane, a phone buzz, only present on some takes.
Open the file in an inspector first and look at what you have: sample rate, bit depth, channel count, peak level. A take recorded at low level and pushed up in post has a noise floor lifted by the same amount, and no plugin recovers that.
The order that works
- Choose the best mic. Boom and lav rarely have the same noise, and switching source is free.
- High pass around 70 to 90 Hz on dialogue, before anything else.
- Remove hum with a narrow notch at the fundamental plus harmonics.
- Only then apply broadband reduction, and use half of what sounds right on a solo listen.
- Fill the gaps with room tone from the same location so silence does not pump.
Why less is more
Broadband denoisers work by learning a noise profile and subtracting it. The maths is spectral, so aggressive settings also remove the low level detail that makes a voice sound present: breath, sibilance tails, room reflections. Six decibels of reduction plus good room tone almost always beats twenty decibels of reduction alone.
What you can do before the plugins
Check whether the problem is really noise. A poly WAV where the boom and the lav are summed together will sound noisier than either alone. Split the file into mono stems first, listen to each track, and build the edit from the cleanest source. That single step fixes more takes than any denoiser.
You can split, audition and level tracks here in the browser. Nothing is uploaded, which matters when the material is under embargo.