Noise Suppression in Slack and Teams: One Toggle vs Three Levels

The quick version

In Slack, click your profile picture, open Preferences, then Audio & video, and under Microphone check the box to enable noise suppression; it removes background sound from your mic in huddles. In Teams, noise suppression is turned on by default with three levels: from the main window select Settings and more, then Settings, then Devices, and turn on the Noise suppression toggle, or set it mid-meeting under More actions, then Settings, then Audio settings.

Slack: one checkbox in Audio & video

Slack documents noise suppression as a microphone preference. Click your profile picture in the sidebar, select Preferences, then Audio & video. Under Microphone you can select a default microphone from the drop-down menu, check or uncheck the box for automatic gain control (which keeps your voice at a constant level for others), and enable noise suppression to remove background sound. To test your mic, say a few words and check that the input level moves up and down while you are speaking.

Slack: when to switch it off

Slack's troubleshooting guide names one tradeoff: in video huddles, high CPU usage can make your computer run slowly. For huddles with many participants, Slack suggests disabling your video or turning off noise suppression may help speed things up. If your machine fans spin up during a big video huddle, the suppression checkbox is one of the two levers Slack points to.

Teams: on by default, with levels

Microsoft says Teams offers three levels of noise suppression on the Teams desktop app, the mobile apps for iOS and Android, Microsoft Teams Rooms on Windows, and Windows Azure Virtual Desktop. It is turned on by default, and the setting you choose carries over to your next meeting or call. To manage it outside a call, select Settings and more, then Settings, then Devices, and turn on the Noise suppression toggle. In a meeting, select More actions, then Settings, then Audio settings in the meeting controls, and use the same toggle.

Teams: the iOS levels explained

On iOS, tap your profile picture, then Settings, then Calling, then Noise suppression, and choose an option. Auto, the default, lets the Teams app optimize the level and is best for most situations. Low suppresses persistent background noise like a computer fan or air conditioner, and Microsoft suggests it when you want to play music for other participants, such as while waiting for a meeting to start. High suppresses all background sound that is not speech.

Teams: background noise only vs voice isolation

In Settings, then Devices, then Audio settings, the Noise suppression options go further. Selecting Background noise only suppresses noises around you and minimizes disruption during a call. Selecting Voice isolation suppresses other voices that might come through your mic, so people in your meeting hear only your voice; Microsoft notes this requires creating a voice profile if you are not using a headset. The same page covers the speaker and mic dropdowns, an automatically adjust mic sensitivity toggle and a test call button. One caveat Microsoft adds: some audio settings may be unavailable depending on policies set by meeting organizers or your IT admin.

Teams: studio and music exceptions

Microsoft lists two cases for backing suppression off. Turn off noise suppression for high-fidelity microphones in a low-noise environment, such as a quiet studio. And for higher fidelity when playing music for other participants in a meeting, Microsoft points to its Share sound from your computer documentation rather than leaving speech-optimized suppression running.

Which one for what?

Our read: if you just want background hum gone, Slack's single checkbox does the job with nothing to configure, and its documented CPU escape hatch is easy to reach. Teams gives more control where it counts: default-on protection you never have to remember, an explicit Low level for music moments, High for loud shared spaces, and voice isolation for the person working in a genuinely noisy room. The catch is spread: the toggle lives in Devices, the levels in Audio settings, and some options can be locked by IT policy.

What to be careful about

• Slack suppression can cost CPU. Slack's own guide suggests turning it off if video huddles slow your computer down.
• Teams is on by default. You may already be filtered; check Devices settings before troubleshooting your mic.
• Voice isolation needs a voice profile if you are not using a headset, per Microsoft.
• High level is speech-first. For music, Microsoft suggests the Low level or its share-sound route instead.
• High-fidelity studio mics are the exception. Microsoft says to turn suppression off there.
• IT policies can remove options. Microsoft notes some audio settings may be unavailable depending on organizer or admin policies.

Sources

Checked October 26, 2026. Features, steps and limits follow each product's own help articles. The guidance on when each shines is ours.

• Slack: Adjust your huddles preferences
• Slack: Troubleshoot audio and video issues in Slack
• Microsoft Support: Reduce background noise in Microsoft Teams meetings
• Microsoft Support: Manage audio settings in Microsoft Teams meetings