Yeah, I wouldn’t recommend doing that.

And that’s not how you establish a PKI or implement AE (authenticated encryption). When I send a voice message e.g. I don’t verbally sign it, that’s actually part of KE (key exchange) protocol.

Same applies to non encrypted, authenticated communication of course.

And in case you are talking about physical face to face communication: I think you’d recognize your family and friends without the help of cryptography.

Edit: if you have any question, feel free to ask! Maybe I misunderstood you? Then I’m sorry