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