Audacity noise reduction: how to remove background noise
To remove background noise in Audacity, select half a second of noise-only audio and choose Effect ▸ Noise Reduction ▸ Get Noise Profile, then select the whole track and apply Effect ▸ Noise Reduction. Alternatively, use the free OpenVINO AI Noise Suppression effect, which cleans up speech without needing a noise profile at all.
Both routes are free. Which one is better depends on the noise, and there are some noises neither will fix — that part usually goes unmentioned, and it is the part that saves you an hour of pointless slider-dragging.
Noise reduction for Audacity
Three routes at a glance:
- Steady hiss or hum, and you have a moment of silence: built-in Noise Reduction. Free.
- Speech, and no clean moment to sample: OpenVINO AI Noise Suppression. Free.
- Noise the first two mangle: a dedicated denoiser plugin.
How we choose: we explain what each method does to the sound, not just which buttons to press, and we state the price of everything we name.
The fast fix: built-in Noise Reduction in three steps
Audacity’s Noise Reduction works by learning what your noise sounds like and then subtracting it. That means it needs a sample of the noise on its own — this is the step people skip, and skipping it is why the effect appears not to work.
- Capture the noise profile. Find a stretch of at least half a second where only the unwanted noise is audible — no speech, no music. Drag to select it, then choose
Effect ▸ Noise Reduction ▸ Get Noise Profile. The dialog closes; nothing appears to happen. That is correct — Audacity has stored the noise fingerprint. - Select the audio to clean. Usually the whole track:
Ctrl+Aon Windows,⌘Aon a Mac. - Apply it. Open
Effect ▸ Noise Reductionagain, adjust the sliders if needed, hit Preview to listen, then OK.
That is the whole procedure. Everything below is about getting a good result rather than merely a result.
Getting the noise profile right
The quality of your profile sets the ceiling on the quality of your cleanup, so it is worth two minutes of care.
Find the cleanest noise you can. Look at the waveform for a flat stretch — the beginning before you started talking, or a pause between sentences. If a chair creaks or a breath lands in your selection, Audacity learns that as “noise” and will attack similar frequencies in your voice.
Half a second is the minimum, not the target. A second or two gives the analysis more to work with.
Profile each recording separately. If you record on different days, the room, the fan and the traffic all differ. A profile from Tuesday will do a worse job on Wednesday’s file.
The pro habit: start every recording by staying silent for five seconds. It costs nothing and guarantees you a clean profile later. If you record regularly, this single change improves your results more than any slider.
What the three sliders actually do
Noise Reduction (dB) controls how much of the profiled noise gets attenuated. Higher removes more — and this is the one to be careful with, because pushing it is exactly what produces the artefacts below. Start low and increase only until the noise stops bothering you, not until it disappears completely.
Sensitivity sets how readily Audacity decides a given sound counts as noise. Raise it and more of the signal gets treated as noise, which cleans more aggressively and eats into the voice sooner.
Frequency Smoothing spreads the reduction across neighbouring frequency bands. A value of 3 is the usual starting point. Raising it is the main fix for the metallic ringing described below.
The honest summary: these three interact, the right settings differ per recording, and nobody can hand you a universal preset. Use Preview constantly, and A/B against the untreated audio rather than judging in isolation.
When it goes wrong
Two failure modes, both caused by asking for too much.
Watery or underwater voice. Push Noise Reduction too far and the voice takes on a warbling, hollow quality — the effect is now removing parts of the speech along with the noise. The fix is to back the reduction off. A recording with a little audible hiss and a natural voice sounds more professional than a silent background with a robot on top of it.
Musical noise. At aggressive settings you get faint tinny or metallic artefacts, sometimes described as ringing or chirping in the background. This is where Frequency Smoothing earns its keep — raise it and the artefacts soften.
A useful rule: aim to reduce noise to the point where a listener stops noticing it, not to eliminate it. Total removal always costs you voice quality.
What noise reduction cannot fix
This effect is built for constant noise — fan hiss, air-conditioning rumble, a fridge hum, electrical whine, buzzes. Steady, unchanging, predictable.
It is the wrong tool for:
One-off clicks, pops and bangs. A door slam or a mouth click is not in the profile and will not be touched. Cut or repair these individually instead.
Room reverb. Echo from a hard, empty room is your voice, arriving late. Noise reduction has no way to distinguish it from the voice itself. No free tool fixes this well — the answer is treating the room or getting closer to the microphone.
Intermittent noise. A passing motorbike, a dog, someone talking in another room. These vary, so a static profile doesn’t match them.
Clipping and distortion. Recorded too loud is recorded too loud. Re-record it.
Recognising which category your problem falls into saves more time than any setting.
The AI route: OpenVINO Noise Suppression
Audacity also has an AI noise suppressor, and it is free. It arrives with the OpenVINO AI Tools plugin, published by Muse Group, installed through MuseHub.
You will find it at Effect ▸ OpenVINO AI Effects ▸ OpenVINO Noise Suppression, with a suppression level, a sensitivity control and a Preview button.
Two differences matter:
It needs no noise profile. The model already knows what speech sounds like, so it separates voice from background without you finding a silent moment. On recordings that never have one — a conversation with no gaps, a file that starts mid-sentence — this is the difference between a usable result and none.
It is optimised for spoken word. That is a genuine strength on podcasts, interviews and voiceover, and a genuine limitation elsewhere. On music it can do strange things to sustained notes and cymbals. For a vinyl rip or an instrumental recording, the classic Noise Reduction effect is usually the better choice.
It also runs entirely on your own computer — nothing uploads, there is no minute limit and there is no subscription. Two requirements: Audacity 3.7.4 or a later 3.x release (this is the single most common reason the effect doesn’t appear in the menu; the plugin does not support Audacity 4 yet), and a plugin install from MuseHub, where you pick which models to download.
Plugin options
If neither built-in route gets you there, dedicated plugins go further. Two worth knowing, priced honestly:
Viator Voice Denoiser is free, and aimed squarely at voice.
Denoiser by Tape It is a paid plugin ($99.99). That is a real investment and only makes sense if you are cleaning audio regularly — for an occasional podcast episode, the free options will get you most of the way.
The three methods compared
| Method | Best for | Needs a noise profile? | Cost |
|---|---|---|---|
| Built-in Noise Reduction | Steady hiss, hum, fan noise; music as well as speech | Yes | Free |
| OpenVINO AI Noise Suppression | Speech with no clean silence to sample | No | Free (needs Audacity 3.7.4+, not yet 4) |
| Viator Voice Denoiser | Voice cleanup inside a plugin chain | No | Free |
| Denoiser (Tape It) | Regular, demanding cleanup work | No | $99.99 |
Noise reduction is not a noise gate
Worth separating, because the two get confused.
Noise reduction subtracts a noise fingerprint from the whole recording, including underneath the speech.
A noise gate simply mutes the audio when it drops below a threshold. The noise vanishes between words and is still there underneath them — which can sound worse, because the background now switches on and off with every sentence.
Gates are useful for a noisy multi-microphone setup where you want inactive microphones silent. For cleaning up a single voice, reduction is the tool.
FAQ
Why does my voice sound watery after noise reduction? Too much reduction. Lower the Noise Reduction slider and raise Frequency Smoothing. Some residual noise with a natural voice always beats a clean background with a damaged one.
I can’t find the OpenVINO effects in the menu.
Check your Audacity version — the plugin needs 3.7.4 or a later 3.x release and does not run in Audacity 4 yet. Update or switch to Audacity 3, restart, and look again under Effect ▸ OpenVINO AI Effects.
Can Audacity remove echo from a room? Not meaningfully. Reverb is your own voice arriving late, and noise reduction cannot separate it. Improve the room or the microphone position instead.
Can it remove a single loud bang? No — one-off sounds aren’t in the noise profile. Edit them out manually or use a repair tool on that selection.
Is noise reduction free in Audacity? Yes. Both the classic Noise Reduction effect and the OpenVINO AI Noise Suppression effect are free, as is Audacity itself.
Should I reduce noise before or after other processing? Early, before compression. Compression raises quiet parts, which makes any remaining background noise louder and more obvious.
Next steps
New to plugins in Audacity? Start with how to use effects and plugins in Audacity — installing them through MuseHub, the realtime effects panel and the formats Audacity 4 loads. The OpenVINO plugin above still needs Audacity 3.
Cleaning noise is one step of a voice chain. Mixing your podcast covers levels and balance once the noise is gone, and the best podcasting plugins covers the processing that follows.
For the rest of what the AI plugin adds — stem separation, transcription, audio upscaling — see AI audio editing in Audacity. If you are digitising records rather than cleaning speech, recording a turntable into Audacity covers surface noise specifically.
Once the voice is clean, podcast sound effects covers what goes on top of it. And if you are still choosing an editor, the best free audio editing software compares Audacity against the alternatives.
Get Audacity and the free OpenVINO AI Tools plugin in one place — download MuseHub free.
