In the olden days of land-line telephones, noise was artificially added to the line so people knew they were still connected to the other person.
Is it possible to add a small amount of "comfort noise" to Teams as an option? Thanks to noise-canceling microphones, when someone is not talking, it is completely silent. You can't tell if you're connected or not without looking.
According to the above Wikipedia article, many VoIP systems have options to add that small background noise or to disable it. Sure seems like it wouldn't be difficult to add.