I used the “ghost frequency” (18.98 hz) whenever we did our initial “meeting from home” when this mess started. After a month, they cancelled the meetings. Whether it worked or not, I like to think that it did and this was my contribution to the advancement of the human race through meeting-less progress. ;)
If you echo the voice back into audio at just the right delay it causes brain freeze in the person speaking. Just blame it on the cheap China electronics.