Steam Community :: Guide :: Using Steam Voice Chat
Headset Microphone Echo :: Help and Tips
[Bug] Microphone/Audio crackly on voice chat (inbound and outbound) · Issue #6747 · ValveSoftware/steam
Try using your headset in other apps.
But voice chat in Steam is broken and has been for a while now.
I tried searching for solutions but none of the old posts some of which were from years ago had any real solutions.
Good luck to all of you.
Once all steps are finished, restart your Steam and check whether the issue of Steam voice chat not working is solved.
Most of the time this is just caused by crosstalk which should never be a problem in well-made gear.