Audio spot lighting is a recent technology that creates focused beams of sound like flashlight beams. It targets specific listeners with sound without others nearby hearing, using nonlinear acoustics and mathematics. An acoustic device fires ultrasonic pulses with small wavelengths, acting like a narrow sound column. It maintains a low beam angle dictated by wavelength, using ultrasound to create extremely narrow sound beams that behave like light beams. This allows controlling sound direction and dispersion.

1. AUDIO SPOT LIGHT
Presented By:
B.HARINATHREDDY

2. CONTENTS
 ABSTRACT
 INTRODUCTION
 THEORY
 BLOCK DIAGRAM
 COMPONENTS
 ADVANTAGES &
 DISADVANTAGES
 CONCLUSION

3. ABSTRACT
 Audio spot lighting is a very recent technology that creates focused beams of sound
similar to light beams coming out of a flashlight. By ‘shining’ sound to one location,
specific listeners can be targeted with sound without others nearby hearing it. It uses a
combination of non-linear acoustics and some fancy mathematics. But it is real and is fine
to knock the socks of any conventional loud speaker.
 This acoustic device comprises a speaker that fires inaudible ultrasound pulses with very
small wavelength which act in a manner very similar to that of a narrow column.

4. INTRODUCTION:
 Audio spot lighting is a very recent technology that creates a
focussed beams of sound similar to light beams coming out of
a flash light.
 Specific listeners can be targeted with sound without others
nearby hearing it.
 It makes use of non-linearity property of air.

5. LOUDSPEAKERS:
Loudspeakers are direct radiating—that they fundamentally a position like device designed to
directly pump air molecules into motion to create audible sound we hear The beam angle of
audible sound is very wide, just about 360 degrees
AUDIO SPOT LIGHT:
In order to focus sound into a narrow beam, you need to maintain a low beam angle that is
dictated by wavelength
The original low frequency sound waves such as human speech or music are applied into an
spotlight emitter device
This low frequency signal is frequency modulated with ultrasonic frequencies Since ultrasonic
frequency is used the wavelength of the combined signal will be in the order of few millimetres
Since the wavelength is smaller the beam angle will be around 3 degree, as a
result thesound beam will be narrow one with a small dispersion
THEORY

6. HOW IS THE SOUND FOCUSED INTO A
NARROW BEAM
 Maintain a low beam angle that is dictated by wavelength.
 The smaller the wavelength, the less the beam angle,
 the more focussed will be the sound.
 The audio spot light uses ultrasonic energy to create extremely narrow beams of sound .
FOCUSED BEAM OF SOUND

7. CONVENTIONAL LOUD SPEAKER Vs AUDIO
SPOTLIGHT

8. BLOCK DIAGRAM

9. COMPONENTS OF AUDIO SPOTLIGHTING SYSTEM
Power Supply
Frequency oscillator Modulator.
Audio signal processor.
Microcontroller.
Ultrasonic amplifier.
Transducer.

10. WORKING
 Ultra sonic frequencies : 21khz to 28khz
 Beam angle : 3 degree
Narrow
beam with small dispersion…
 It uses ultrasonic energy to create extremely
narrow beams of sound that behaves like
beams of light

11. DISPERSION OF SOUND BEAM
Figure shows the dispersion of sound beam from an audio spotlighting emitter. Even after
traveling a distance of 10m the beam covers only an area of 3.2 meter square

12. RANGE OF HEARING

13. TYPES OF MODES
Directed Audio Mode
Projected Audio Mode

14. DIRECTED MODE
 Direct mode requires a clear line of approach
from the sound system unit to the point where
the listener can hear the audio.
 To restrict the audio in a specific area this
method is appropriate

15. PROJECTED MODE
 Also know as virtual mode
 The mode of operation the sound beam from an
emitter is made to reflect from a reflecting surface
such as wall surface or a diffuser surface
 A virtual sound source creates an illusion of sound
source that emanates from source where no
physical loudspeaker is present.

16. APPLICATIONS:
AUTOMOBILES MUSEUMSSAFETY OFFICIALS
MILITARY APPS
AUDIO/VIDEO
CONFERENCING
PUBLIC ANNOUNCEMENT RETAIL SALES

17. ADVANTAGES :-
•Can focus sound only at the place you want.
•Ultrasonic emitter devices are thin and flat .
•The directed sound travels much faster .
•Dispersion can be controlled.
•Highly cost effective and longer life span.
•Requires same power as required for regular
speakers.
•There is no lag in reproducing the sound

18. DISADVANTAGES
• Lack of mass production. i.e, each unit must be hand
made.
• The most common form of distortion is clipping.

19. FUTURE OF AUDIO SPOTLIGHTING:
Even the best loudspeakers are subject to distortion and their omni directional sound is
annoying to the people in the vicinity who do no wish to listen. Audio spotlighting system
holds the promise of replacing conventional speakers. It allows the user to control the
direction of propagation of sound. The audio spotlight will force people to rethink their
relationship with sound. Audio spotlighting really “put sound where you want it”.

20. CONCLUSION:-
Even the best loudspeakers are subject to distortion and their omni-
direction sound is annoying to the people in the vicinity who do not wish
to. The audio spotlight will force people to rethink their relationship with
sound. Audio spotlighting really

21. 1)Thomas D. Kite, John T. Post, and Mark F. Hamilton.
Parametric array in air: Distortion reduction by pre-
processing. Journal of the Acoustical Society of
America.
2) www.silentsound.co.za – Silent sound.
3)www.wikipedia.org - Sound from Ultrasound.
4) www.howstuffworks.com
5)www.techalone.com-audio spotlighting.
6)www.holosonics.com
REFERENCE :-