Patent ID: 7796676

Claim:
An acoustic data communication system comprising: a first acoustic data communications device comprising: (i) an input terminal operable to receive electrical message data having a power spectrum which lies substantially over a first bandwidth, (ii) a spread spectrum encoder operable to spread the power spectrum of the message data substantially over a second bandwidth which is greater than the first bandwidth and which extends over a frequency band which is audible to humans; and (iii) an electroacoustic convertor operable to convert the data output by said spread spectrum encoder into corresponding acoustic signals having a bandwidth that extends over a frequency band audible to humans and for transmitting the acoustic signals into the atmosphere; and a second acoustic data communications device comprising: (i) an acoustoelectric converter operable to receive acoustic signals from the atmosphere and to convert the received acoustic signals into corresponding electrical signals; (ii) a spread spectrum decoder operable to despread the power spectrum of the received signals; (iii) a message regenerator operable to regenerate the message data transmitted by said first acoustic data communications device from the despread signals output by said spread spectrum decoder; (iv) a processor operable to process the regenerated message data and operable to output a control signal in dependence upon the regenerated message data and (v) an output coupled to the processor and operable to receive the control signal and to output a human discernable response in dependence upon the control signal.