Show HN: TCP/UDP over sound
Slightly unrelated but curious; have there been any attempts to transfer data as sound? I don't mean sound converted to electricity, or to represent 0s and 1s, but using a specific frequency range to represent 1, another range to represent 2, another for 3... I don't know the terms for these things.<p>Using vibrations instead of electrons to transmit data over a wire?<p>Do creatures like dolphins do this?