18-02-2010, 12:53 PM
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INTRODUCTION
What is audio spot lighting
Invented by Dr. F. Joseph Pompei.
It is the Production of focused beams of Sound
Combination of Non-Linear Acoustics & Fancy Mathematics.
Uses Ultra-sonic Energy to create Narrow beams of sound
Non Linearity of the AIR aid the device for its working
Device used: Parametric Array
How does ordinary sound system work
Piezoelectric Tweeters.
Speakers.
Woofers etc.
What ordinary audible sound & Conventional Loud Speakers lack
Difficulty in reproducing clean bass.
Has to rely on a large woofer/enclosure combination for it.
THEORY
Audio spot lighting is a technology that creates focused beams of sound similar to light beams coming out of a flashlight.
By Ëœshiningâ„¢ sound to one location, specific listeners can be targeted with sound without others nearby hearing it.
The Audio Spotlight & Hyper Sonic Sound Technology (developed by American Technology Corporation), uses ultrasonic energy to create extremely narrow beams of sound that behave like beams of light.
WORKING
Low Beam Angle is required to focus the Sound.
Smaller the Wave length, Lesser the Beam Angle.
Another way to Focus sound is to increase Aperture size of Speakers(10m dia for 20Hz) practcally difficult.
Technology Overview
Developed by American Technology Corporation
Uses ultrasonic energy to create extremely narrow beams of sound that behave like beams of light.
Ultrasonic sound has very small wavelengthâ€in the millimeter range and lies beyond the threshold of human hearing
NON-LINEARITY OF AIR
When inaudible ultrasound pulses are fired into the air, it spontaneously converts the inaudible ultrasound into audible sound tones.
A device known as a parametric array employs the non-linearity of the air to create audible by-products from inaudible ultrasound, resulting in an extremely directive, beamlike wide-band acoustical source.
The ultrasound column acts as an airborne speaker
Human speech, as well as music, contains multiple varying frequency signals.
Then came the idea of using pure ultrasound signals as a carrier wave.
Airborne ultrasounds of
28kHz are envelope-
modulated with audio
signals. Inherent non-linearity
of the air works as a
de-modulator.
Thus de-modulated sounds impinge on our eardrums. We can hear those sounds!
Similar to the idea of Amplitude Modulation (AM).
The speech and music signals are mixed with the pure ultrasound carrier wave, and the resultant hybrid wave is then broadcast.
Berktayâ„¢s equation holds strong here P2(x,t)=KPc2-2/ t2(E(x,t)
SPECIAL FEATURES OF AUDIO SPOTLIGHT
¢ Creates highly FOCUSED BEAM of sound
¢ Sharper directivity than conventional loud
speakers using Self demodulation of finite
amplitude ultrasound with very small
wavelength as the carrier
¢ Uses inherent non-linearity of air for
demodulation
INTRODUCTION
What is audio spot lighting
Invented by Dr. F. Joseph Pompei.
It is the Production of focused beams of Sound
Combination of Non-Linear Acoustics & Fancy Mathematics.
Uses Ultra-sonic Energy to create Narrow beams of sound
Non Linearity of the AIR aid the device for its working
Device used: Parametric Array
How does ordinary sound system work
Piezoelectric Tweeters.
Speakers.
Woofers etc.
What ordinary audible sound & Conventional Loud Speakers lack
Difficulty in reproducing clean bass.
Has to rely on a large woofer/enclosure combination for it.
THEORY
Audio spot lighting is a technology that creates focused beams of sound similar to light beams coming out of a flashlight.
By Ëœshiningâ„¢ sound to one location, specific listeners can be targeted with sound without others nearby hearing it.
The Audio Spotlight & Hyper Sonic Sound Technology (developed by American Technology Corporation), uses ultrasonic energy to create extremely narrow beams of sound that behave like beams of light.
WORKING
Low Beam Angle is required to focus the Sound.
Smaller the Wave length, Lesser the Beam Angle.
Another way to Focus sound is to increase Aperture size of Speakers(10m dia for 20Hz) practcally difficult.
Technology Overview
Developed by American Technology Corporation
Uses ultrasonic energy to create extremely narrow beams of sound that behave like beams of light.
Ultrasonic sound has very small wavelengthâ€in the millimeter range and lies beyond the threshold of human hearing
NON-LINEARITY OF AIR
When inaudible ultrasound pulses are fired into the air, it spontaneously converts the inaudible ultrasound into audible sound tones.
A device known as a parametric array employs the non-linearity of the air to create audible by-products from inaudible ultrasound, resulting in an extremely directive, beamlike wide-band acoustical source.
The ultrasound column acts as an airborne speaker
Human speech, as well as music, contains multiple varying frequency signals.
Then came the idea of using pure ultrasound signals as a carrier wave.
Airborne ultrasounds of
28kHz are envelope-
modulated with audio
signals. Inherent non-linearity
of the air works as a
de-modulator.
Thus de-modulated sounds impinge on our eardrums. We can hear those sounds!
Similar to the idea of Amplitude Modulation (AM).
The speech and music signals are mixed with the pure ultrasound carrier wave, and the resultant hybrid wave is then broadcast.
Berktayâ„¢s equation holds strong here P2(x,t)=KPc2-2/ t2(E(x,t)
SPECIAL FEATURES OF AUDIO SPOTLIGHT
¢ Creates highly FOCUSED BEAM of sound
¢ Sharper directivity than conventional loud
speakers using Self demodulation of finite
amplitude ultrasound with very small
wavelength as the carrier
¢ Uses inherent non-linearity of air for
demodulation
