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Visvesvarya Technological UniversityBelagum , Karnataka
AUDIOSPOTLIGHTING
Technical SeminarBy
Chengodi.P(1ico7ec008)8th sem ECE
HOD:Prof.Vaibhav
Guided by:Mrs.Hema
Impact College Of Engineering And Applied SciencesBanglore-92,Karnataka
Bachelor of engineeringIn
Electronics And Communication Engineer
IS IT POSSIBLE TO CONFINE SOUND TO A SMALL AREA???
WHAT IS AUDIO SPOTLIGHTING?
Audio spotlighting is a technology that creates focused beams of sound
‘Shining’ sound to one location to target specific listeners
Invented by Joseph Pompei at MIT
HOW ???
Combines non-linearity of air & narrow ultrasound beams
Ultrasound beams are beyond human audible range
HOW ???
Ultrasound beams - used as carrier Highly directive Device used- parametric array Modulation and demodulation
HOW ???
As the beam moves through air gradual distortion takes place in a predictable way due to non-linear property of air & gives rise to audible components
Ultrasound beam acts as an airborne speaker
AUDIO SPOTLIGHT CREATES FOCUSED BEAM OF SOUND UNLIKE CONVENTIONAL LOUD SPEAKERS
Audio spotlight looks like a disc-shaped loudspeaker.
When one points the flat side of the disc in your direction, you hear whatever sound he's chosen to play for you.
COMPONENTS USED
Transducer Signal Processor Amplifier
PARAMETRIC SPEAKER-AUDIO
SPOTLIGHT Airborne ultrasounds of
28kHz are 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!
TO ACHIEVE MORE FOCUSED SOUND
Small beam angle Smaller the wavelength
CONVENTIONAL LOUDSPEAKERS
Spreads in all directions (360 degrees) Requires large aperture size for higher
directivity (i.e. 10m diameter for 20Hz) which is not practical.
MODES OF AUDIO SPOTLIGHT
Direct audio
Projected audio
FEATURES OF AUDIO SPOTLIGHT
Creates highly FOCUSED BEAM of sound
Sharper directivity than conventional loud speakers
Uses non-linearity of air for demodulation
Cost effective
FEATURES OF AUDIO SPOTLIGHT
Thin and flat & do not require a mounting cabinet
Focused or directed sound travels much faster
No lag in producing sound
APPLICATIONS
Military & security communications
Museums Audio/video
conferencing Automobiles
APPLICATIONS
Entertainment Exhibition & sales Public
announcements
CONCLUSION“put sound where you want”
Even the best loud speakers are prone to distortion & omni direction of sound may be at times is annoying to few listeners
Audio spotlighting would replace loudspeakers in near future and allows user to control direction of sound
THANK YOU