How to Remove Background Noise in Audacity (August 2026) Guide

Background noise is the enemy of clean audio. Whether you are recording a podcast, a voice-over, or a video narration, that constant hum, hiss, or fan noise can drag down your production quality fast. The good news? You can remove background noise in Audacity using a built-in effect that costs nothing.

Audacity ships with a powerful Noise Reduction tool designed specifically for this purpose. You do not need plugins, subscriptions, or expensive software. In this guide, I will walk you through the entire process step by step, explain every setting, and share tips I have learned from editing hundreds of hours of audio.

If you have ever wondered how to remove background noise in Audacity without making your voice sound robotic, you are in the right place. Let us start with what this tool actually does.

What Is Audacity Noise Reduction and When Should You Use It?

Audacity’s Noise Reduction is a built-in effect that identifies constant background noise and reduces it across your entire track. It samples a section of pure noise, builds a profile of those unwanted frequencies, then suppresses them while leaving your voice or music intact.

This tool works best on consistent, steady noise. Think fan hum, air conditioner drone, microphone hiss, electrical buzz, or steady room tone. If the noise is constant, Audacity can usually handle it.

It is not a magic eraser, though. Variable sounds like background chatter, keyboard clicks, dog barks, or traffic bursts are much harder to remove. For those, you may need manual editing or a Noise Gate, which I cover later in this guide.

Common use cases include cleaning up podcast recordings, voice-over takes, music demos, interview audio, and video voice tracks. Basically, if your recording has a steady layer of unwanted noise behind your audio, this is the tool to reach for first.

How to Remove Background Noise in Audacity: Step-by-Step

The process to remove background noise in Audacity follows six straightforward steps. The secret is capturing a clean noise profile before you apply any reduction.

Step 1: Import your audio file. Open Audacity, then drag and drop your audio file into the timeline. You can also use File > Import > Audio from the top menu. Your track will appear as a waveform in the main window.

Step 2: Select a section of pure noise. Zoom in on your waveform and find a spot where only background noise is present. This is usually a gap between words or a few seconds of silence at the start. Click and drag to highlight one to two seconds of that noise-only section. This selection is what Audacity will learn from, so make sure no voice or music sneaks in.

Step 3: Get the noise profile. Go to Effect > Noise Reduction in the top menu. In the dialog that appears, click the button labeled “Get Noise Profile.” Audacity captures the frequency fingerprint of your selected noise and closes the window automatically. The profile is now stored in memory.

Step 4: Select the entire track. Click anywhere on your track, then press Ctrl+A on Windows or Cmd+A on Mac to select all audio. You can also double-click the track. If you only want to clean a specific section, just highlight that portion instead.

Step 5: Open Noise Reduction again. Return to Effect > Noise Reduction. The dialog now shows three sliders instead of the “Get Noise Profile” button. This means Audacity is ready to apply the profile it captured in Step 3.

Step 6: Preview, adjust, and apply. Click the Preview button to hear a sample of how your audio will sound after reduction. If it sounds good, click Apply. If you hear distortion or artifacts, reduce the settings and preview again. I recommend starting conservative and increasing only if needed.

That is the complete process. The most important step is the second one. A clean noise profile makes everything downstream sound better, so take your time selecting the right section.

Understanding Noise Reduction Settings: dB, Sensitivity, and Frequency Smoothing

When you open the Noise Reduction dialog for the second time, you see three sliders. Each one controls a different aspect of the effect, and understanding them is the difference between clean audio and robotic mush.

Noise Reduction (dB) controls how aggressively Audacity removes the noise. Higher numbers mean more removal. The default is 12 dB, which is a solid starting point for most recordings. Push this above 20 dB and you risk introducing artifacts, which are those watery, metallic, or robotic sounds that make audio unpleasant. I usually stay between 6 and 15 dB depending on how severe the noise is.

Sensitivity determines how strictly Audacity matches the noise profile against your audio. The default is 6.00, and most of the time you should leave it there. Lower values like 1 or 2 make the effect more conservative and less likely to touch your voice. Higher values above 10 make it more aggressive but can start eating into your actual audio signal. For podcast and voice work, keeping sensitivity between 3 and 6 gives the best balance.

Frequency Smoothing spreads the reduction across neighboring frequency bands, which prevents abrupt changes that sound unnatural. The default is 3 bands. Values between 1 and 6 generally work well. Higher smoothing can reduce artifacts on music or complex audio, while lower smoothing is fine for solo voice tracks.

If you are unsure where to start, use these defaults: Noise Reduction at 12 dB, Sensitivity at 6, and Frequency Smoothing at 3. Preview the result, then nudge values up or down from there.

Other Tools: Noise Gate and Notch Filter Explained

Noise Reduction is not the only tool Audacity offers for cleaning audio. Two other effects handle specific noise problems better than Noise Reduction alone.

Noise Gate works differently from Noise Reduction. Instead of identifying and reducing noise across the whole track, a Noise Gate simply mutes or lowers audio that falls below a chosen threshold. When you stop talking, the gate closes and silence takes over. This is perfect for recordings where your voice is clearly louder than the background noise, because it cuts the room tone during pauses without processing your speech at all.

To use Noise Gate, go to Effect > Noise Gate. Set the Gate threshold to a level just above your background noise but below your quietest speech. A typical starting point is between -40 and -30 dB. Preview and adjust until silence gaps sound clean without cutting off word endings.

Notch Filter targets a single specific frequency, which makes it the go-to tool for electrical hum. If you hear a persistent buzz at 60 Hz (common in North America) or 50 Hz (common in Europe and other regions), a Notch Filter can surgically remove it. Go to Effect > Notch Filter, set the frequency to 60 or 50, and apply. The Q-value controls how wide the cut is, with a higher Q meaning a narrower, more surgical removal.

So when do you use each? Use Noise Reduction for general constant noise like hiss and fan hum. Use Noise Gate when your voice is clearly louder than the background and you just want silence between words. Use Notch Filter when you have a specific electrical hum at a known frequency. You can also combine all three for stubborn recordings.

Tips for Best Results When Removing Background Noise

Getting clean audio is as much about technique as it is about settings. Here are practical tips from audio professionals and forum communities that consistently produce better results.

Record a noise profile before you speak. Before hitting record on your actual content, capture three to five seconds of pure room silence with your microphone live. This gives you a perfect noise-only section to sample later. Just remember to trim it out of the final edit.

Do multiple light passes instead of one heavy pass. Applying Noise Reduction twice at 6 dB often sounds better than once at 12 dB. Heavy single passes introduce artifacts, while lighter passes are gentler on your voice. Press Ctrl+R on Windows or Cmd+R on Mac to repeat the last effect quickly.

Normalize after noise reduction. Removing noise can lower your overall volume. Once your noise is cleaned up, select all audio and go to Effect > Normalize. Set the peak amplitude to around -3 dB. This brings your levels back up to a professional standard without clipping.

Record in a treated space whenever possible. No amount of software can fully replace a quiet room. Close windows, turn off fans and air conditioning, put your phone on silent, and use acoustic treatment if available. Prevention always beats correction.

Use keyboard shortcuts to speed up your workflow. Press Ctrl+A to select all, Ctrl+R to repeat the last effect, and Ctrl+Z to undo if a pass sounds wrong. These shortcuts save hours over the course of editing multiple episodes.

Avoid trying to fix variable noise. If your recording has a dog barking or people talking in the background, Noise Reduction will struggle. For those moments, manually edit or silence the offending sections instead of running the effect across the whole track.

Troubleshooting Common Audacity Noise Reduction Problems

Sometimes the result is worse than the original. Here is how to fix the most common problems people run into.

Your audio sounds watery, robotic, or metallic. This happens when Noise Reduction is applied too aggressively. The effect is removing frequencies that belong to your voice along with the noise. Lower the Noise Reduction dB value, reduce Sensitivity, and try lighter multiple passes instead of one heavy application. Artifacts almost always mean your settings are too high.

There is still noise after applying the effect. First, check that you captured a proper noise profile from a clean noise-only section. If your profile accidentally included voice or music, the effect will not work correctly. Re-select a better section and capture a new profile. Also confirm you selected the entire track before applying, not just a small portion.

Word endings or soft syllables get cut off. This usually means you applied a Noise Gate with the threshold set too high. Lower the gate threshold so it only closes during true silence, not during quiet speech. A threshold around -40 dB is a safer starting point for most voice recordings.

The noise is intermittent, not constant. Noise Reduction is designed for steady, unchanging noise. If the background sound varies, like chatter, traffic, or random clicks, the effect will not catch it. For intermittent noise, use manual editing, select and silence those moments individually, or consider a specialized repair tool.

Your track volume dropped after noise reduction. This is normal. Reducing noise also reduces overall signal. Run Effect > Normalize afterward with a peak of -3 dB to restore healthy levels. You can also use Effect > Amplify for a quick volume boost.

Frequently Asked Questions

Wrapping Up: Clean Audio Is Within Reach

Learning how to remove background noise in Audacity comes down to one core workflow: capture a clean noise profile, select your track, and apply Noise Reduction with conservative settings. The tools are free, the steps are straightforward, and with a little practice the results sound professional.

Remember the golden rules. Record a few seconds of room silence at the start of every session for a clean profile. Prefer multiple light passes over one heavy pass. Normalize your audio afterward to restore healthy levels. And whenever possible, record in a quiet space so you have less to fix later.

Now open Audacity, load up a recording, and try it yourself. The first time you hear that background hiss disappear, you will understand why this technique is a staple of every audio editor’s workflow.