How to Remove Background Noise in Audacity Without the Robot Voice

A humming fridge, a whirring laptop fan or traffic outside the window can make a great podcast episode or voiceover sound amateur. Audacity's Noise Reduction effect is free and surprisingly good at cleaning it up, as long as you give it the right sample and don't push it too hard.

How to remove background noise in Audacity, step by step

1. Find a few seconds of your recording where nobody's talking, just the background noise, and select it.
2. Go to Effects, then Noise Reduction, and click Get noise profile.
3. Select all the audio you want to clean. Press Ctrl + A (Cmd + A on a Mac) for the whole track.
4. Open Effects, then Noise Reduction again.
5. Adjust the settings. Tick Residue to hear only what will be removed, then switch back to Reduce.
6. Click OK and listen back.

Once you're happy with your settings, the shortcut Ctrl + R (Cmd + R on a Mac) reapplies Noise Reduction to a selection straight away.

The catch: too much noise reduction makes you sound robotic

The temptation is to turn everything up until the noise disappears completely. Don't. Audacity's own guide warns that a poor noise profile or the wrong sensitivity setting can create artifacts, which sound like random short bursts of tones or a watery, metallic voice. A little remaining hiss sounds far more natural than a voice that's been scrubbed until it warbles.

Start gentle, listen with headphones, and only go further if you need to. If the noise sample you picked isn't typical of the whole recording, for example the fan switched on halfway through, take a new profile from the noisier section.

Which Audacity tool for which noise

Problem	Best tool	How it works
Constant hiss or a fan	Noise Reduction	Learns the noise from a sample and removes it
Room sound between sentences	Noise Gate	Quietens anything below a threshold
A steady electrical hum	Notch Filter	Removes one specific frequency
Sudden sounds like a dog bark or door slam	None of the above	Cut it out or re-record that line

Using a Noise Gate after Noise Reduction

Audacity suggests a neat combination: apply gentle Noise Reduction first, then a Noise Gate. The gate quietens anything below a threshold, so the gaps between your sentences go silent while your voice is untouched. Using both means you can keep the Noise Reduction lighter, which sounds cleaner.

1. Select a section of just background noise.
2. Open Effects, then Noise Gate, choose Analyse Noise Level and click OK. Audacity recommends a threshold.
3. Select the audio you want to gate.
4. Open Noise Gate again, choose Gate, enter that threshold and click OK.

Getting rid of electrical hum

A low, steady hum is usually electrical. Audacity's guide explains mains hum is 60Hz in North and Central America and 50Hz in most other countries. Use the Notch Filter at that frequency, and if some hum remains, repeat at multiples such as 100Hz and 150Hz. If you're unsure of the frequency, Analyze, then Plot Spectrum, will show you the peak.

Prevent noise in the first place

Audacity's own best-practice advice is to get a quiet environment before you record, because no effect beats a clean recording. A few easy wins:

• Turn off fans, air conditioning and noisy appliances while you record.
• Record in a room with soft furnishings, which soak up echo.
• Get closer to your microphone and turn the input down, so your voice is loud and the room is quiet.
• Record five seconds of silence at the start, so you've got a clean noise sample for later.

While you're recording, keep an eye on the level meter. Audacity says normal speech ideally sits around -18 to -12 dB; if it hits the red, you're clipping, which no noise tool can fix. My guide to podcast editing software covers tools that automate some of this.

Exporting your cleaned-up audio

Choose File, then Export Audio. MP3 is the safe choice for podcasts and voiceovers, though Audacity notes Opus and M4A (AAC) give better quality at the same file size.

A quick before-and-after check

Before you export, compare the cleaned audio with the original. Undo the effect, listen to ten seconds, redo it and listen again. If the voice sounds thinner or slightly underwater in the cleaned version, back the settings off. Then listen on two different devices, such as headphones and your phone speaker, because problems that hide on one often show up on the other. It takes two minutes and it's the difference between audio that sounds edited and audio that just sounds clear.

My verdict

Take a noise profile, apply Noise Reduction gently, and finish with a Noise Gate if the gaps still sound busy. Use the Notch Filter for hum, and don't try to rescue sudden noises with effects; cut them instead. Most of all, record in a quiet room so there's less to fix. For a wider look at podcast workflows, see my guide to podcast SEO.

Frequently asked questions

Where is noise reduction in Audacity?

Under Effects, then Noise Reduction. You need to click Get noise profile on a noise-only selection first.

Why does my voice sound robotic after noise reduction?

The settings are too strong or the noise profile wasn't representative. Use gentler settings and take a new profile.

Can Audacity remove background music or voices?

Noise Reduction works best on constant noise like hiss or hum, not changing sounds like music or speech.

How do I remove hum in Audacity?

Use the Notch Filter at 50Hz or 60Hz depending on your country, and at multiples if needed.

What is the Noise Gate in Audacity for?

It quietens anything below a threshold, which silences the gaps between sentences.

Is Audacity's noise reduction free?

Yes. Audacity is free and Noise Reduction is built in.