If ever we have to, we could do both, and then still call it "humming" since it would still be that and it's a very pithy (two syllables) word for it. It's als

If ever we have to, we could do both, and then still call it "humming" since it would still be that and it's a very pithy (two syllables) word for it. It's also possible that humming has little to do with sight and more to do with using the volume of humming to help indicate the strength of the sense of the room -- that actually is a very useful aspect of humming. However, humming became a thing concommitantly with participation by people with limited sight, which is probably why I remember that as a motivation, but in fact it might not have been! It's been a long time now that the IETF uses humming...