An acoustic coupler is made for coupling a modem to a phone microphone. A modem is made for harnessing the phone line directly. Both are for creating long runni

An acoustic coupler is made for coupling a modem to a phone microphone. A modem is made for harnessing the phone line directly. Both are for creating long running connections. This is made for short messages sent thru the air. The most obvious novel use for this would would be IoT without a network.