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Anoob Hamza Mohammed | 1HM03EC006 | VIII ECE |
H.M.S.I.T, Tumkur
Audio Spotlighting
Contents :
AdvantagesDisadvantagesLimitationsApplicationsConclusionBibliography
IntroductionHow does It work?HistoryThe InventorWhy audio
spotlight?The Audio
spotlighting System
Technical Overview
Introduction :
Audio Spotlighting is a very recent technology that focuses a beam of sound to the intended audience.
The Audio Spotlight uses ultrasonic energy to create extremely narrow beams of sound.
What is Audio Spotlight ?
Now Let Us All Watch A Video To Understand
The Effectiveness Of Audio Spotlight System. This video is being
demonstrated by Dr. F. Joseph
Pompei.
Demonstration :
Two Ways To Use Audio Spotlight:
Conventional Loudspeaker & Audio Spotlighting Ultrasonic Emitter
The human ear is sensitive to frequencies from 20Hz to 20KHz.
No single loud speaker element can operate efficiently over this range of frequencies.
Hence the speaker manufacturers carve the audio spectrum into smaller sections, which require multiple transducers.
Range Of Hearing :
Audio spotlighting exploits the property of non-linearity of air.
Sound may be projected to just about any desired point in the listening environment.
How does it work?
A device known as a parametric array employs the non-linearity of the air to create audible by-products from inaudible ultrasound.
Non-Linearity of Air :
The ultrasound column acts as an airborne speaker.
As the beam moves through the air, gradual distortion takes place in a predictable way.
This gives rise to audible components.
1. Music & Ultrasound2. Sound And Ultrasonic Wave As
Carrier Wave To Build A Hybrid Wave3. Hybrid Wave
4. Hybrid Wave Distorts With Air To Produce Audible Sound Wave 5. Finally Audio signals reach the destination.
History :The US govt. worked on creating Ultrasonic sound for using it as a weapon for many years unsuccessfully.
In 2000, Dr. F. Josef Pompei PhD (MIT) created successfully a device which emits ultrasonic sound which he called Audio Spotlight.
In 2002 Elwood Norris, owner of American technology corporation developed a similar technology which he called Hypersonic Sound.
Dr. Joseph Pompei
Inventor of audio spotlight ™ .
The Inventor:
The ability of Audio spotlight to direct or focus sound into a tight beam, which no other audio reproduction device available today provides.
The opportunities for applying this characteristic to the reproduction of sound are limitless.
Audio spotlight creates ultrasonic sound that travels in a straight line rather than spreading out like lower frequency sound.
Why Audio Spotlight?
The Audio Spotlighting System3 Major Components
A Thin, Circular Transducer Array
A Signal Processor
An Amplifier
Signal processor converts the music from audio source to a highly complex ultrasonic signal.
This signal is then amplified and emitted into air by the transducer.
Focus sound where you want it and no place else.
Ultrasonic emitter devices are thin and flat and do not require a mounting cabinet.
The focused or directed sound travels much farther in a straight line than conventional loudspeakers
Advantages :• Its characteristics allow it to perform in ways conventional loudspeakers cannot • Its characteristics allow it to perform in ways conventional loudspeakers cannot
Museums
Applications :• Its characteristics allow it to perform in ways conventional loudspeakers cannot • Its characteristics allow it to perform in ways conventional loudspeakers cannot
AutomobilesAudio/video conferencingPaging systems
Military applications
Helpful for blind people
Sound bullets
Virtual home theatre
Safety officials
Besides consumer electronics, the entertainment industry is expected to be influenced by this development.
Virtual reality, in large-scale applications, has been brought another step closer.
Conclusion :• Its characteristics allow it to perform in ways conventional loudspeakers cannot • Its characteristics allow it to perform in ways conventional loudspeakers cannot
Audio spotlighting technology can replace the bulkier, inefficient speakers and provide far better results than we ever heard.
With Audio spotlighting technology , hearing aids may produce the entire audio spectrum and may also shrink in size.
Bibliography :
Audiospotlights.com. 2005. http://www.audiospotlights.com/index.html
Holosonics.com. 2002. (July 21, 2008) http://www.holosonics.com/technology.html
M.Yonema and J.Humoto. The audio spotlight: An application of nonlinear interaction of sound waves to a new type of loudspeaker design, J. Acoustical Society of America,
vol. 73, no.5, pages 1532-1536, May 1983
www.howstuffworks.com
Thank You
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