All you need to know is the channel bandwidth (say 20-50khz) and noise floor power relative to rx power to give maximum data transfer rate (Shannon-Hartle theor

All you need to know is the channel bandwidth (say 20-50khz) and noise floor power relative to rx power to give maximum data transfer rate (Shannon-Hartle theorem). Capacity = (Bandwidth) * log2 (1 + recieve_power / noise_floor_power). There is also a lot of em noise going on - just like sound. I would expect sound to be many orders of magnitude less power effecient/bit than EM - but the principles basically the same