TL;DR:
When multiple people are in a Teams meeting in the same room a feedback loop can be created, causing a horrible howling, screeching noise. Teams will soon automatically mute the microphone and speakers of anyone who joins the meeting and is near to someone with audio on. Due early to late March 2023 on Teams desktop.

Details:
When you join a Teams meeting that already has other participants physically in the same room, you will be notified before joining the meeting that several people have joined the meeting already and that your speaker and microphone will be turned off to prevent an echo. You can turn audio back on at any time.


Availability:
Due early to late March 2023 on Teams desktop.

Source, related links, and references:
MC514081.

Check status:
Microsoft 365 Roadmap ID 92391.

Page originally published:
12th February 2023 and kept up to date.