    Machine Listening Group Digital Life Consortium

    A beam of light can be controlled in many ways - it can be
    aimed at one person in a crowd, spread to fill a room, or
    projected to create rich, distant imagery.

    We can now do these very same things with sound.

    To my friends in the UK:

    Thanks to those who have contacted me regarding the BBC piece;
    I'm happy it was so well received.  I recently had a very
    polite British visitor, who seemed to enjoy the demonstration
    a great deal... click the photo to see who it was.

    The Audio SpotlightTM, invented and developed at the MIT Media
    Lab, is a device which uses subtle nonlinear properties of the
    air to create an extremely narrow Sound BeamTM.  This beam of
    sound behaves just like a beam of light - 'shining' it at a
    specific listener allows only that person to hear it, and
    projecting it against a surface creates an acoustic 'image' at
    the point of reflection.  It is the first device that provides
    total control over both the location and distribution of high
    quality sound, something impossible to achieve with
    traditional loudspeakers.

    The circular transducer is very thin, and can be constructed
    in a variety of sizes and configurations as needed.  A typical
    Audio Spotlight transducer has an active area of approximately
    1 foot diameter, and, depending on size and frequency content,
    projects an approximately three-degree wide beam of sound
    audible to well over 100 meters.  Harmonic distortion has been
    reduced to close to that of a traditional loudspeaker, sound
    level is quite appreciable (on the order of 80-90dBA) at
    several meters, and frequency response, depending on size,
    extends down to a few hundred Hertz, and upwards beyond the
    range of hearing. Continued research is being conducted on all
    facets of the technology.

    While still under development, we are testing applications of
    the device in collaboration with several of our Media Lab
    Sponsors in preparation for eventual commercial release.

    Put sound wherever you want it.TM

    F. Joseph Pompei pompei@media.mit.edu

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