How to Remove Background Noise in Audacity: Best Settings, Hum Fix, and Echo Limits
How the two-step Get Noise Profile workflow works in Audacity 4.0.1, what the three Noise Reduction sliders actually do, why Audacity can't remove room echo or changing noise, and how to clean tracks when you don't have a clean noise sample.
Updated November 5, 2026Michael NguyenTested October 2026
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Quick answer
To remove steady background noise in Audacity 4.0.1, highlight 1 to 2 seconds of pure room noise where nobody is talking, open Effect > Noise Removal and Repair > Noise Reduction, and click Get Noise Profile. Then select the whole track (Ctrl+A or Cmd+A), open Noise Reduction again, and apply it using the classic 12 dB, 6, 3 voice settings (or Audacity 4's 6 dB, 6, 6 defaults). Because Audacity subtracts a static noise sample, it cannot remove changing noise (traffic, café clatter, dogs) or hollow room echo. When you don't have a clean noise sample or need to fix room echo or an MP4 video, Audo AI's Remove noise and Audio enhancer clean files up to 10 hours and 10 GB in your browser for $3.00 an hour (first minute free).
| Capability | Audacity 4.0.1 (Built-in Noise Reduction) | Audacity + Intel OpenVINO AI Plugins | Audo AI (Remove noise & Audio enhancer) |
|---|---|---|---|
| How it works | Two-step noise subtraction: highlight at least 2,048 samples of isolated noise to capture a Noise Profile first | Local AI noise suppression plugin (Windows/Linux build) | Cleans noise and room echo automatically in the browser, with no silent Noise Profile needed |
| Changing noise (traffic, clatter, wind, barking) | No. Audacity's manual notes it is only meant for constant noise like hum, whistle, or hiss | Yes, in supported Audacity 3.7.x builds (not compatible with Audacity 4.0.x) | Yes: removes changing traffic, wind, café chatter, and background music while keeping speech intact |
| Room echo / reverb removal | No built-in de-reverb effect (Audacity's Reverb and Echo effects add echo rather than removing it) | No dedicated room de-reverb in Audacity 4.0.x | Yes: Remove echo and Audio enhancer with a 0–100% Strength slider |
| Video files (MP4, MOV, MKV) | Audio-only editor: requires installing an external video-import library just to read the audio track, and cannot export video | Audio export only | Accepts MP4, MOV, MKV, WebM, and AVI up to 10 GB and gives the video back with its picture untouched |
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Play Original, then Cleaned.
Cleaned removes the chatter and dishes.
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How to remove background noise in Audacity 4.0.1 (step by step)
Audacity's built-in Noise Reduction works like a stencil: you show it a couple of seconds where only the unwanted hiss or hum is playing, and it subtracts those frequencies from the rest of your track. In Audacity 4.0.1, the effect moved under Effect > Noise Removal and Repair > Noise Reduction (in older 3.x builds, it sat directly under the main Effect menu).
Because of how that stencil works, Step 1 is everything. If you accidentally highlight a breath, a lip smack, or the tail end of a spoken word when you grab your Noise Profile, Audacity will treat human voice frequencies as noise and carve them out of your entire recording.
Step 1: Highlight 1 to 2 seconds of pure background noise
Drag across a quiet gap on the waveform that contains only the room hiss or fan hum you want gone, with zero speech or breathing. Audacity requires a minimum of 2,048 samples (about 0.05 seconds at 44.1 kHz), and 1 to 2 full seconds gives a much cleaner fingerprint.
Step 2: Capture the fingerprint with Get Noise Profile
Go to Effect > Noise Removal and Repair > Noise Reduction and click Get Noise Profile. The window closes right away; that's normal and means Audacity saved your noise sample in memory.
Step 3: Select the audio you want to clean
Press Ctrl+A (Windows/Linux) or Cmd+A (Mac) to highlight the full track, then open Effect > Noise Removal and Repair > Noise Reduction a second time.
Step 4: Preview Step 2 sliders and click OK
Keep the radio button on Reduce, test with Preview, and click OK to apply. (Tip: switch the radio button to Residue during Preview to hear only what Audacity is taking out. If you hear faint words in the Residue, lower your settings.)
Best noise reduction settings in Audacity (and how to remove background hum)
Audacity's Noise Reduction dialog has three sliders under Step 2, and their factory defaults in Audacity 4.0.1 are 6, 6, and 6. It's tempting to drag all three up to 24 when a recording is noisy, which is what causes the watery, tinkling 'musical noise' sound that makes over-processed Audacity tracks sound metallic or robotic.
For spoken voice (podcasts, voiceovers, interviews), the classic recipe is 12 dB, 6, 3 (or 6 dB, 6, 6 for very light hiss): set Noise reduction (dB) between 6 dB and 12 dB, which sets how far the noise is turned down. Keep Sensitivity right at 6.00 (raising it makes Audacity attack quiet speech consonants, while lowering it leaves fizz behind words). Set Frequency smoothing (bands) to 3 (or up to 6 bands) to blend neighboring frequencies so the voice doesn't sound metallic or robotic; if your speaker sounds boxy, drop Frequency smoothing closer to 3. If your noise is a loud 15+ dB, running two gentle passes of 6 dB with a fresh Noise Profile between them almost always sounds cleaner than a single 12 dB pass.
If your recording has a steady electrical buzz or ground-loop hum from an unshielded USB cable or AC power (50 Hz in Europe/UK/Australia, 60 Hz in North America) alongside mic rumble, Audacity also includes Effect > EQ and Filters > High-Pass Filter (set around 80 Hz with a 12 dB/octave rolloff to clear low mic-stand thumps) and Notch Filter (set to 50 Hz or 60 Hz to carve out a narrow power-line hum before you run Noise Reduction).
Why Audacity can't remove room echo, changing noise, or MP4 video noise
As the official Audacity manual points out, built-in Noise Reduction only works on constant noise that stays the same from second to second. When a motorcycle drives past your window, someone clatters dishes in the next room, or a laptop fan spins up mid-sentence, there is no matching quiet sample for Get Noise Profile to subtract.
Audacity also has no built-in tool for removing room echo. Effect > Delay and Reverb > Reverb and Echo add echo to dry tracks rather than taking it out. And if you highlight the tail of a room echo as your Noise Profile, Audacity treats the speaker's own voice frequencies as noise and makes the track sound underwater.
Intel's OpenVINO plugins added local AI noise suppression to Audacity 3.7.x on Windows and Linux, but Audacity's support docs note they don't work in Audacity 4.0.x. Audacity is also audio-only: even if you install an external library to open the sound from an MP4 or MOV file, it only exports audio files (WAV, MP3, FLAC), never a video.
Audacity 4.0.1 Noise Reduction (free, desktop)
Great when you recorded WAV/MP3 audio in a quiet room and want to shave 6 to 12 dB of steady preamp hiss or computer fan hum using a clean 2-second Noise Profile.
Audo AI Remove noise & Remove echo (first minute free, then $3.00/hr)
Built for recordings where the noise changes over time (traffic, wind, barking dogs, café noise), where there is no silent gap to grab a Noise Profile, or where bare walls added hollow room echo.
Audo AI Remove noise from video (MP4, MOV, MKV, WebM, AVI)
Cleans the audio inside video files up to 10 hours and 10 GB in your browser and gives your video back with the cleaned sound and the original picture untouched.
When Audacity's built-in effect is enough vs. when to pair it with Audo AI
Many podcasters and voice actors edit in Audacity and run tricky files through Audo AI first:
Audacity 4.0.1 built-in Noise Reduction
If your audio recording is in a padded room with nothing more than a steady 6 dB mic hiss or fan hum, and you remembered to record 2 seconds of silent room tone at the start.
Audo AI Remove noise & Audio enhancer
When background noise changes while the speaker talks, when the room sounds hollow or echoey, when you don't have a clean gap for Get Noise Profile, or when your recording is an MP4 or MOV video, with the first minute free (no sign-up) and full files up to 10 hours and 10 GB for $3.00 an hour.
Clean changing noise and room echo without a Noise Profile
Drop your WAV, MP3, MP4, or MOV file into Audo's Remove noise or Audio enhancer. Try the first minute free with no sign-up, then export clean audio for $3.00 an hour before cutting in Audacity.
Questions
What are the best noise reduction settings in Audacity?
For spoken voice, use the classic 12 dB, 6, 3 settings (or Audacity 4's 6 dB, 6, 6 defaults): Noise reduction between 6 dB and 12 dB, Sensitivity at 6.00, and Frequency smoothing between 3 and 6 bands. Pushing Noise reduction or Sensitivity much higher makes the voice sound metallic or robotic; if you have louder changing noise, run the track through Audo AI's Remove noise instead.
How do I remove background hum in Audacity?
For a steady 50 Hz or 60 Hz electrical hum, apply Effect > EQ and Filters > Notch Filter set to 50 Hz or 60 Hz, or highlight 1 to 2 seconds of the isolated hum and use Effect > Noise Removal and Repair > Noise Reduction > Get Noise Profile. If the hum varies or overlaps with room reflections, clean the file in Audo AI's Audio enhancer.
Can Audacity remove echo or room reverb from a recording?
No. Audacity has no built-in de-reverb effect (its Reverb and Echo effects add reverb to dry tracks, and sampling room echo as a Noise Profile carves out the speaker's voice). To remove hollow room echo from a WAV, MP3, or video file, use Audo AI's Remove echo or Audio enhancer.
Can Audacity remove background noise from a video?
Audacity is an audio-only editor: even if you add an external library to read the audio from a video, Audacity only exports audio files (WAV, MP3, FLAC) without the picture. To clean the sound in an MP4 or MOV file and download the video with its picture untouched, use Audo AI's Remove noise from video.