How to remove background noise from a screen recording on a Mac

The short answer

• Prevent it: use the best microphone you have, sit close to it, and record in a quiet room with soft furnishings. Five minutes of setup beats any filter.
• Fix it with built-in tools: import the recording into iMovie, select the clip, click the Noise Reduction and Equalizer button, and turn on Reduce background noise. Use the lowest setting that works, or voices start to sound hollow.
• Fix it in Shotnix: open the recording, go to the Audio tab, and turn on Enhance voice. It removes background noise and hum from your voice on your Mac, and the export evens out loudness to −16 LUFS.

Where the noise comes from

Different noises have different fixes, so it helps to name the one you hear.

• Steady hiss: the microphone's own noise, made worse when you raise the input level to make up for sitting too far away.
• Hum or buzz: electrical interference, often from a charger, a USB hub, or audio cables running alongside power cables.
• Room noise: air conditioning, fans, a fridge, traffic. It sits under every word you say.
• Echo: hard walls and bare floors bouncing your voice back into the microphone.
• Clicks and dings: your keyboard and mouse, and notification sounds from the Mac itself.

Record cleaner audio in the first place

Every filter trades a little voice quality for less noise. The less noise you record, the less filtering you need.

• Choose the microphone on purpose. A USB microphone or a wired headset beats a laptop microphone at arm's length. In the ⌘⇧5 toolbar, pick it under Options → Microphone; in Shotnix, pick it on the recording bar before you start.
• Get close and stay there. Distance matters more than price: the closer you are, the louder your voice is compared with the room. With a USB microphone, a hand's width or two away and slightly off to the side keeps breath pops out.
• Set the level once. In System Settings → Sound, select your microphone under Input, speak at a normal volume, and set Input volume so the level meter moves well but never fills up.
• Quiet the room. Switch off fans and air conditioning while you record, close the window, and pick a room with curtains, a rug, or a sofa to soak up echo.
• Silence the Mac. Turn on Do Not Disturb from Control Center → Focus so notification sounds and banners stay out of the recording.
• Keep Bluetooth headphones for listening. Many switch to a lower-quality mode while their microphone is in use, so record with the Mac's microphone or a wired one.
• Test before the real take. Record 15 seconds and play it back on headphones. Speakers hide hiss and hum that viewers with earbuds will hear.

Recording a call? Turn on Voice Isolation

Macs from 2018 and later have a Voice Isolation mic mode that filters background sound out of your microphone during calls. In an app that supports Mic Modes, such as FaceTime, click the Video icon in the menu bar, click Mic Mode, and choose Voice Isolation. On macOS Monterey and Ventura, Mic Mode is in Control Center instead.

It only works in apps that support Mic Modes, and it cleans up the sound that app sends. That helps the people on the call, and if they turn it on as well, their voices reach your Mac already cleaned up. To get their side into your recording, capture system audio: on macOS 27 or later, the ⌘⇧5 toolbar has Options → Include System Audio. Shotnix records system audio on every macOS version it supports and keeps your microphone separate, so you can set each level afterwards.

Method 1: Reduce background noise in iMovie

1. Open iMovie (free on the App Store if it isn't installed), create a new movie, choose File → Import Media, and add your recording. Drag it to the timeline.
2. Select the clip in the timeline, then click the Noise Reduction and Equalizer button in the adjustments bar above the viewer.
3. Select the Reduce background noise checkbox and drag the slider. Start low, play a few seconds, and raise it only until the noise stops being distracting.
4. Optionally, choose Voice Enhance from the Equalizer pop-up menu to bring your narration forward.
5. If your voice is quiet, click the Volume button, then click Auto to boost the average level.
6. Choose File → Share → File to export the cleaned-up video.

Note. Push the slider too far and voices turn thin, watery, or robotic, and no setting brings back words the noise covered. QuickTime Player has no audio cleanup at all, so among Apple's free apps, iMovie is the practical choice.

Method 2: Enhance voice in Shotnix

1. Record with Shotnix and turn on Microphone on the recording bar, plus System audio if the app's sounds matter. Your voice and the computer's sound are recorded separately, so you can balance them later.
2. Stop the recording and it opens in the editor. To clean up an older video, choose Open With → Shotnix in Finder, or drop the file on the app.
3. Open the Audio tab in the inspector and turn on Enhance voice. Shotnix uses Apple's voice isolation on your Mac to remove background noise and hum, evens out your level, and keeps the voice in sync with the picture.
4. Under Sound, set Voice and Computer sound separately so the narration sits clearly on top of the app's own sounds.
5. For one loud moment, such as a notification ding, split around it with S, select that clip, and mute it or fade it.
6. Leave Even out loudness on under Export, then press ⌘E. The whole mix lands at −16 LUFS without clipping.

Remove background noise with Shotnix →

What −16 LUFS means, in plain words

A peak meter shows how close the loudest instant comes to distorting. It says little about how loud a video feels. LUFS (loudness units relative to full scale) measures loudness the way people hear it, averaged across the whole video. The numbers are negative, and closer to zero is louder.

−16 LUFS is a common target for spoken audio online, and it's the level Apple recommends for podcasts. A video that lands there isn't noticeably quieter or louder than the one before it, so nobody reaches for the volume keys.

Even out loudness measures your finished mix and turns the whole thing up or down to reach that level, so the balance you set between voice and computer sound stays intact. It never clips to get there: if one moment is far louder than the rest, the whole mix is held back slightly, which is one more reason to mute that stray ding.

What noise removal can't fix

• Distortion. If your voice clipped because the input level was too high, removing noise won't undo it. Lower the level and record again.
• Words buried in noise. A filter removes sound; it can't bring back syllables the noise covered.
• Other voices. Voice isolation is built to keep speech, so a colleague talking nearby may stay in.
• Strong echo. Processing can soften it, but a room with soft surfaces fixes it properly.
• Sounds from the Mac itself. Enhance voice works on your microphone. A video playing on screen or an alert sound belongs to the computer's sound, so turn Computer sound down or mute that clip instead.

Questions