AUDIO SPOTLIGHTING

Presented by, Bi j i Raju

S3.MCA#1203 MBIT,Anchal

CONTENTINTRODUCTION

TECHNOLOGY OVERVIEW

RANGE OF HEARING

WORKING

BEAM DISPERSION

ARCHITECTURE

MODES OF LISTENING

ADVANTAGES & DISADVANTAGES

APPLICATIONS

FUTURE OF AUDIO SPOT LIGHTENING

CONCLUSION

What is Audio Spotlighting????

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

Uses ultrasonic energy to create extremely narrow beams of sound that behaves like beam of light.

Audio spot light is developed by American Technology Corporation.

TECHNOLOGY OVERVIEWTECHNOLOGY OVERVIEW

• Audio spot lighting works by emitting harmless high frequency ultrasonic tones that human ear cannot hear.

• To produce highly focused audio signal we use loud speakers with larger aperture size

• Parametric array employs the non linearity of the air to create audible by products From inaudible ultrasonic sound , resulting in extremely directive and beamlike sound.

As the beam moves through the air gradual distortion takes place in a predictable way. This give rise to audible components that can be accurately predicted and precisely controlled.

TECHNOLOGY OVERVIEWTECHNOLOGY OVERVIEW

RANGE OF HEARING

• Human ear - 20 Hz to20,000Hz.

• No single loud speaker can operate efficiently over such wide range of frequencies.

• By using this technology it is possible to design a perfect transducer which can work over a wide range of frequency which is audible to the human ear.

WORKING

• The original low frequency sound wave such as human speech or music is applied into an audio spotlight emitter device.

• This low frequency signal is frequency modulated with ultrasonic frequencies range with wave length of few millimeters.

• Since the wavelength is smaller the beam angle will be around 3 degree, as a result the sound beam will be a narrow one with a small dispersion.

FIG:- F.JOSEPH POMPEI AT THE MEDIA LAB OF THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY DEMONSTRATES HOW INVISIBLE ULTRASONIC WAVES, AS ILLUSTRATED HERE, COULD HELP "STEER" SOUND. (ABCNEWS.COM)

Fig: AUDIO SPOTLIGHTING EMITTER

WORKING…….

WORKING…….

• Due to the nonlinearity property of air new sounds are formed within the wave.

• The new frequencies (sounds) will be added into the sound wave by the air itself.

• The new sound signal generated will be corresponding to the original information signal with a frequency in the range of 20 Hz to 20 KHz .

• Since we cannot here the ultrasonic sound, we only hear the new sounds that are formed by the nonlinear action of the air

COMPONENTS OFAUDIO SPOTLIGHTING SYSTEM

Power Supply.Power Supply.

Frequency oscillator.Frequency oscillator.

Modulator.Modulator.

Audio signal processorAudio signal processor

Microcontroller.Microcontroller.

Ultrasonic amplifier.Ultrasonic amplifier.

Transducer.Transducer.

1. Power Supply: works off DC, ultra sonic amplifier requires 48v for working and low voltage for other components.

2. Frequency oscillator: generates ultra sonic frequency signals (21,000 Hz to 28,000Hz).

3. Modulator : convert the source information into ultrasonic signals. In addition, error correction is needed to reduce distortion without loss of energy.

4. Microcontroller: takes care of the functional management of the system.

5. Audio signal processor: The audio signal is sent to an electronic signal processor circuit where equalization, dynamic range control, distortion control and precise modulation are performed to produce a good quality sound signal.

6. Ultrasonic amplifier: High- efficiency ultrasonic power amplifies the frequency modulated wave in order to match the impedance of the integrated transducers. So that the output of the emitter will be more powerful and can cover more distance.

7. Transducer : It is1.27 cm thick and17”diameter.Produces audibility up to 200 meters with better clarity of sound.

• Has the ability of real time sound reproduction with zero lag.

• These transducers are arranged in form of an array called parametric array in order to propagate the ultrasonic signals from the emitter and thereby to exploit the nonlinearity property of air.

MODES OF LISTENINGMODES OF LISTENING

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.

Projected or Virtual mode:

 For this mode of operation the sound beam from an emitter is made to reflect from a reflecting surface.A virtual sound source creates an illusion of sound source that emanates from a surface.

This method is appropriate when we want to send the information to a large number of people.

 Small size

 Single source

 Ultimate control in audio placement

 Minimizes noise pollution

 Ease of installation

 Lowest maintenance cost 

 Reduced feedback

ADVANTAGES

ADVANTAGES

Small size

Single source

Ultimate control in audio placement

Minimizes noise pollution

Ease of installation

Lowest maintenance cost 

Reduced feedback

DISADVANTAGES

 Lack of mass production. i.e, each unit must be hand made.

 The most common form of distortion is clipping. An LED on top of the Audio spotlight system reports clipping, which is also perceptible to the listener as a kind of a 'chirping' effect. If any signal produces distortion, the input level of the source is reduced until perceptible distortion is eliminated.

APPLICATIONS AutomobilesBeam alert signals can be directly propagated from an announcement device in the dashboard to the driver. Presently Mercedes-Benz buses are fitted with audio spotlighting speakers so that individual travellers can enjoy the music of there on interest.

2.Retail sales: Provide targeted advertising directly at the point of purchase.

3.Safety officials: Portable audio spotlighting devices for communicating with a specific person in a crowd of people.

4.Public Announcement: Highly focused announcement in noisy environments such as subways, airports, amusement parks, traffic intersections etc.

5.Emergency rescue: Rescuers can communicate with endangered people far from reach..

7.Military applications: Ship – to – ship communications and shipboard announcements.

8.Audio/video conferencing: Project the audio from a conference in four different languages, from a single central device without the need for headphones.

9.Sound Bullets: Jack the sound level 50 times human threshold of pain, and an offshoot of audio spotlighting sound technology becomes a non-lethal weapon.

6.Entertainment system: In home theatre system rear speakers can be eliminated by the implementation of audio spotlighting and the properties of sound can be improved

11.Museums: In museums audio spotlighting can be used to describe about a particular object to a person standing in front it, so that the other person standing in front of another object will not be able to hear the description.

FUTURE OF AUDIO SPOT LIGHTENING

Holds the promise of replacing conventional speakers.It allows the user to control the direction of propagation of sound. Will force the people to rethink their relationship with the sound.It really “put sound where you want it”.

CONCLUSION

Audio spotlighting is really going to make a revolution in sound transmission and the user can decide the path in which audio signal should propagate. Due to the unidirectional propagation it finds application in large number of fields. Audio spotlighting system is going to shape the future of sound and will serve our ears with magical experience..

REFERENCES

1. www.thinkdigit .com

2. www.holosonics .com

3. www.spie .org

4. www.houstuffworks.com

5. www. Tec alone .com

Thank You