San Diego company, American Technology Corp, reckons it can help make the sound engineer’s dream come true and get rid of the bulky loudspeaker. Big advances in small loudspeaker technology have been made in the last 10 years, but there has been no escape from the fact that to deliver a full audio frequency range with any volume, a speaker has to be big. But American Technology has grasped an idea that has been floating about in the ether for many years – that of distorting the atmosphere itself to create sound – and proved to its own satisfaction that it can make it work. It has got to the point where it has filed patent applications on the technique, which it calls the Norris Acoustical Hetrodyne Effect. It says the technique mixes ultrasonic waves accoustically to create new waves that can be heard as sound – the audible sound is generated indirectly through a conversion process that takes place within directed ultrasonic energy waves so that the sound appears in midair. Inventor of the system Elwood Norris was also responsible for development of an ultrasonic Doppler device that evolved into the Sonogram, and he has also invented a linear tracking tone arm, a cordless microphone, miniature radios, headset devices and audio cue circuitry. The company is not giving much away, but says it has completed its proof-of-concept prototype and is preparing for industry and media demonstrations. It claims that most forms of distortion are eliminated, and that its testing indicates virtually perfect sound reproduction across the entire audible frequency band and beyond.
