AN ELECTRIC EAR

Northern Advocate, 7 December 1935, Page 8

AN ELECTRIC EAR

AN AUCKLAND INVENTION ASTOUNDING CLAIMS MADE. VIOLATION OF PRIVACY. [Special to “Northern Advocate .”l AUCKLAND, This Day. "An electric ear,” through which conversations in ordinary tones can be heard a distance of 150 feet has been shown by an anonymous inventor, who is an Auckland electrical engineer, to the police, who urged him not to divulge the details of the design because, although protected by patent rights, they might be unscrupulously used. The instrument is no larger than an average sized apparatus used by people hard of hearing, but entirely of different principle, the chief components being a tiny variable condenser and a small mercury vapour tube and small earphone, and battery of three dry cells such as are used in an electric torch. Experiments have proved embarrassing to the inventor, as he can hear private conversations in the radius of his workshop and private home. Experiments have led him to design a small variable condenser, enabling him to select sounds which he wishes to hear instead of listening to jumbled noises. He can also gauge the direction from which sounds come. One one occasion, he inadvertently heard a private and personal remark that was being made in a “sound prooi telephone box” in front of the Post Office. On another ocacsion he heard two voices discussing criminal exploits. By operating the directionfinder he located the speakers in a hotel bar. On entering the hotel, he recognised these voices as the voices he had heard outside, and he also recognised the face of one man who had a criminal record. The inventor says that the apparatus is unlikely to be of any commercial value, because it is unsuited as an aid for bad hearing. It might, however, be used to give audible warning of approaching aircraft. <