Hi C0410,
May I know whether you are using built-in internal or external audio/cam device?
Have you tried to uninstall and then reinstall the latest version of audio/video device drivers to check this issue?
You can try test call to check whether your mic, speaker, and camera are working correctly. See under
Make a test call
You may also check your speaker, cam settings when you’re in a meeting, select More options … button > Show device Settings gear button in your meeting controls. For your reference:
Manage audio settings in a Teams meeting
Moreover, you may refer to the article to check whether your device is qualified/certified device for Teams client. For your reference:
Microsoft Teams certified devices
Your time and understanding will be highly appreciated.
Best regards,
Shyamal