It uses a beam of ultrasound as a "virtual acoustic source", enabling unprecedented control of sound distribution. Disney was amongst the first major corporations to adopt it for use at the Epcot Center, and many other application examples are shown on the Holosonics website.Īudio Spotlight is a narrow beam of sound that can be controlled by the same precision as light. Joseph Pompei of MIT developed technology he calls the "Audio Spotlight", and made it commercially available in 2000 by his company Holosonics, which according to their website claims to have sold "thousands" of their "Audio Spotlight" systems. Joseph Pompei of the Massachusetts Institute of Technology in 1998 fully described a working device that reduced audible distortion essentially to that of a traditional loudspeaker.Īs of 2014 there were known to be five devices which have been marketed that use ultrasound to create an audible beam of sound.į. These problems went unsolved until a paper published by Dr. This technology was originally developed by the US Navy and Soviet Navy for underwater sonar in the mid-1960s, and was briefly investigated by Japanese researchers in the early 1980s, but these efforts were abandoned due to extremely poor sound quality (high distortion) and substantial system cost. Another possibility are future applications for true stereo sound, where one ear does not hear what the other is hearing.
The navigation instructions for example are only interesting for the driver in a car, not for the passengers. It can be used for personal audio, either to have sounds audible to only one person, or that which a group wants to listen to. In commercial applications, it can target sound to a single person without the peripheral sound and related noise of a loudspeaker. Wikileaks has published technical specifications of such sound weapons.Ī sound signal can be aimed so that only a particular passer-by, or somebody very close, can hear it. There has been speculation about military sonic weapons that emit highly-directional high-intensity sound however, these devices do not use ultrasound, although sometimes thought to do so. For this reason, most systems are mounted overhead, like lighting. Anything that interrupts the beam will prevent the ultrasound from propagating, like interrupting a spotlight's beam. There are some limitations with this approach.