This page claims one narrow frequency slot above hearing, beeps on it once a second,
and listens for the other eleven. Then it talks: messages go out as sound and arrive
at whoever is close enough to hear them. No network, no pairing, no room code —
the only channel is the air between your speakers and their microphone.
—Idle. Turn your volume up to about half, then start.
Room idle
Nothing said yet. Anything you send goes out as sound and reaches
whoever is close enough to hear it — nobody else, and nothing over the network.