The Japanese idiom ishin-denshin refers to "an unspoken mutual understanding" and literally translates as "what the mind thinks, the heart transmits." It's also the apt name of a new Disney microphone device that inaudibly transmits sounds through the human body.
It's easiest to think of Ishin-Den-Shin as a silent walkie-talkie: One person uses a microphone to record audio, which the microphone then converts into an inaudible signal. In order to transmit the inaudible message, the speaker must touch the receiver's ear while holding the microphone, at which point the receiver will be able to hear the message. The audio can only be heard through finger-to-ear contact, "as if the finger would be whispering the recorded sounds."
Ishin-Den-Shin, which this week received an honorary mention at the prestigious Ars Electronica Festival, was developed by Disney Research in Pittsburgh. From the research team:
"Secrets, messages and whispers can then be transmitted from person to person in physical contact with each others. Bodies become a broadcasting medium for intimate, physical, sound communication."
Ishin-Den-Shin is one of several existing examples of human-based audio transmission. Google Glass, the wearable headset, uses bone conduction technology to ensure only the wearer will be able to hear the headset's voice commands.
[Images courtesy of Disney Research]