A PRESENTATION ON

AUDIO-SPOTLIGHTING

BY-

NIKHIL ANAND SRIVASTAVA3rd YEAR - MECHANICAL ENGG.

SEC - JROLL NO - 02

IS IT POSSIBLE TO CONFINE SOUND TO A SMALL AREA ?

Basic Idea

• Audio Spotlighting is a very recent technology that creates focuses 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.

• The Audio Spotlight uses ultrasonic energy to create extremely narrow beams of sound that behaves like beams of light.

Basic Idea (Contd.)

• Ultrasonic sound has very small wavelength in the millimeter range and lies beyond the threshold of human hearing.

• Low beam Angle is required to focus the sound.• Smaller the wavelength.• Another way to focus sound is to increase aperture

size of speakers(10m diameter for 20Hz)practically difficult.

AUDIO SPOTLIGHT CREATES FOCUSED BEAM OF SOUND UNLIKE CONVENTIONAL LOUD

SPEAKERS

AUDIO SPOTLIGHT LOOKS LIKE A DISK-SHAPED LOUDSPEAKER TRAILING A WIRE WITH A SMALL LASER GUIDE BEAM MOUNTED IN THE MIDDLE

• When one points the flat side of the disk in your direction, you here whatever sound one’s chosen for you.

Working principle

• Frequency modulated signal travel through air, non-linearity property of air comes into action which slightly changes the sound wave.

• Due to change in a sound wave (ultrasonic), new sounds are formed within the wave.

• New sound signal corresponds to the original information signal in the range 20 HZ-20 KHZ.

• Inherent nonlinearity of air works as a demodulator & thus demodulated sound impinge on our eardrums. We can here those sounds.

• AUDIO SPOTLIGHTING EMITTER

Modes of Audio-Spotlighting

• DIRECTED AUDIO MODE

• PROJECTED AUDIO MODE

Comparison between Conventional Speakers & Audio-Spotlighting

• CONVENTIONAL SPEAKERS

• AUDIO-SPOTLIGHTING

Features• Can focus sound only at the specific place one’s

want.• Sharper directivity than conventional loudspeakers.• Uses non-linearity of air for demodulation.• Focused or directed sound travel much faster.• Highly cost effective.• No lag in reproducing the sound & requires low

power.

Applications

• AUTOMOBILES: Beam alerts signals can be directly propagated from an announcement device in the dashboard to the driver.

• RETAIL SALES: Provide directly advertising at the time of purchase.

Applications (Contd.)

• SAFETY OFFICIALS: Portable audio spotlighting devices for communicating with a specific person in the crowd of people.

• MILITARY APPLICATION: Ship to ship communication & shipboard announcement.

• MUSEAUMS: In museums audio spotlight can be used to describe about a particular object to a person standing in front of it, so that the other person standing in front of the other object will not be able to here the discription

Applications (Contd.)

• ENTERTAIRMENT SYSTEMS: In home theater systems rear speakers can be eliminated by the implementation of audio-spotlighting & the properties of sound can be improved

• PUBLIC ANNOUNCEMENT: Highly focused announcement in a noisy environment such as airports, subways, traffic intersections etc.

Conclusion

• Audio-Spotlighting really going to make a revolution in sound transmission and the user can device the path in which audio signal should propagate.

• Audio spotlighting going to shape the future of sound & serve our ears with magical experience.

• So we conclude- Audio-Spotlighting really “put sound where you want it.” & will be “A REAL BOON OF FUTURE”.

THANK YOU