How Noise Suppression Works in Teams Meetings

Teams Noise Suppression Generates Clear Audio Feeds for Teams Meetings

Office 365 Notification MC224751 announces the introduction of AI-based noise suppression in Teams meetings. According to Microsoft 365 roadmap item 68694, the feature will “automatically remove unwelcome background noise during your meetings. AI-based noise suppression works by analyzing an individual’s audio feed and using specially trained deep neural networks to filter out the noise and retain only the speech signal. This is an update to the existing noise suppression. Users will now have control over how much noise suppression they want. The “High” setting is new and will suppress more background noise.”

The feature rolled out for Teams for Windows clients in late 2020. On April 23, 2021, Microsoft posted message center notification MC252330 to announce that noise suppression for Teams meetings will be available for the Teams desktop client for Mac with a deployment starting in late April. The deployment will finish in August. This is Microsoft 365 roadmap item 82826.

Windows PCs must support Advanced Vector Extensions 2 (AVX2) to allow suppression to work. This is the original requirement that used to exist for background blur in meetings; Microsoft downgraded the requirement to AVX earlier this year. Given that most modern workstations support AVX2, this shouldn’t be a big problem.

AI-Based Noise Suppression

Microsoft began demonstrating AI-based noise suppression for Stream video playback at the Ignite 2019 conference and shipped the feature in June 2020. A Microsoft Technical Community post explains how deep neural networks are used to identify background noise in an individual’s audio feed and filter out everything but the person’s voice in the feed passed to a Teams meeting. Other meeting participants only hear what someone says rather than noise occurring in the background.

Noise suppression is automatically applied to recordings of Teams meetings stored in the Stream Azure-based service or OneDrive for Business, so the suppression applied by the Teams client is disabled when a meeting is recording.

The Teams client also disables suppression when live captions are used during meetings, possibly due to the processing needed to capture and recognize speech which is then transformed into captions.

Device Settings

Users can update the device settings in their profile (Figure 1) to choose the level of suppression in meetings. The choices are:

• Auto: Teams monitors the degree of audible background noise in a meeting and tunes suppression up or down to removes non-voice sounds like barking dogs or the rustling of papers.
• Low: Persistent background noise is suppressed, such as a computer or ceiling fan or air conditioner. Microsoft suggests that you use this setting when music is playing in the background.
• High: Suppresses all background noise that Teams considers not to be speech.
• Off: Noise suppression is disabled. Maybe you’re lucky enough to conduct meetings in low noise environments and can use this option.

Noise suppression applies to the sound generated by the microphone used for a meeting, not the audio feeds for other meeting participants. The idea is that you know about potentially distracting noises in your local environment and can therefore decide what level of suppression is needed. If everyone enables noise suppression, the meeting audio should be clear and distinct.

In most cases, it’s best to leave the option at Auto unless you have a reason to choose a different option. The AI might be better at detecting background noise than you are.

Enabling noise suppression consumes computer resources to analyze the sound captured by the microphone and remove unwanted noise. Higher levels of suppression consume more resources, so if a workstation begins to run hot or is resource constrained, you can disable noise suppression or select the Low option to see if this helps.

Teams-Certified Devices

Noise suppression during a Teams meeting does not remove the goodness to be had by using a Teams-certified device (headsets, speakerphones, desk phones, etc.) during calls. These devices deliver noise canceling and better audio quality for what you hear as well as better microphone performance. Noise suppression is all about making the audio feed from your workstation as clear as possible; devices designed for Teams focus on making what you hear as well as what you say as clear as possible.

During a Meeting

The noise suppression option set in your profile becomes the default for all meetings. If you need to change because specific conditions exist for a meeting, the same controls are available in Device settings when a meeting is active.

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