Hi,
It's unusual that all mics seem to be affected, hopefully it's not a voice transmission problem on the systemboard
Try the following first and check if the problem is resolved.
* [https://www.hardreset.info/devices/samsung/samsung-galaxy-note20-ultra-5g/wipe-cache/|Wipe the cache partition] and check.
* Start the phone in [https://www.verizon.com/support/knowledge-base-232913/|safe mode] and check if it works OK. If it does then a ''downloaded app'' is the cause of the problem. The trick is to find out which one it is. You will need to uninstall each ''downloaded app'' one by one and test the phone in normal mode between each uninstall, to see if ti is working OK. When it does the last ''downloaded app'' that was uninstalled was the culprit. A ''downloaded app is one that you downloaded and installed and wasn't pre-installed on the phone when you first got it.''