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A seminar on AUDIO SPOTLIGHTING. Presented by RAKESH B (1BY06EC044). Under the guidance of Prof. ANIL KUMAR D. CONTENTS. INTRODUCTION THEORY WORKING COMPONENTS AND BLOCK DIAGRAM TYPES OF MODES ADVANTAGES APPLICATIONS CONCLUSION BIBLIOGRAPHY. INTRODUCTION.
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A seminar on AUDIO SPOTLIGHTING Presented by RAKESH B (1BY06EC044) Under the guidance of Prof. ANIL KUMAR D
CONTENTS • INTRODUCTION • THEORY • WORKING • COMPONENTS AND BLOCK DIAGRAM • TYPES OF MODES • ADVANTAGES • APPLICATIONS • CONCLUSION • BIBLIOGRAPHY
INTRODUCTION • Audio Spotlighting was invented by Dr. F. Joseph Pompei. • Production of focused beams of sound. • Uses ultrasonic energy to create narrow beams of sound. • Non-linearity of the air aid the device for its working. • Device used: Parametric Loudspeaker or Array.
THEORY • Audio spot lighting is a 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. • The Audio Spotlight uses ultrasonic energy to create extremely narrow beams of sound that behave like beams of light.
Cont… • 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, lesser the beam angle. • Another way to focus sound is to increase aperture size of speakers(10m diameter for 20Hz) practically difficult.
Cont… AUDIO SPOTLIGHT CREATES FOCUSED BEAM OF SOUND UNLIKE CONVENTIONAL LOUD SPEAKERS … Audio spotlight looks like a disc-shaped loudspeaker, trailing a wire, with a small laser guide-beam mounted in the middle.
WORKING (Speech or music) (21k to 28k Hz) Audio Spotlighting Emitter
Cont… • Frequency modulated signal travels 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 20Hz to 20kHz. • Inherent non-linearity of the air works as a • de-modulator and thus de-modulated sounds impinge on our eardrums. We can hear those sounds. • The ultrasonic envelope acts as an airborne speaker.
COMPONENTS • Power supply • Frequency oscillator • Modulator • Audio signal processor • Microcontroller • Ultrasonic amplifier • Transducer
MODES OF LISTENING • Direct Mode • Projected Mode
COMPARISON BETWEEN CONVENTIONALSPEAKERS & AUDIO SPOTLIGHTING CONVENTIONALSPEAKERS AUDIO SPOTLIGHTING
ADVANTAGES Can focus sound only at the place you want. Ultrasonic emitter devices are thin and flat and do not require a mounting cabinet. Focused sound travels much faster in a straight line than conventional loudspeakers. Dispersion can be controlled - very narrow or wider to cover more listening area.
Cont… Highly cost effective. Low maintenance and longer life span. Requires low power. No lag in reproducing the sound.
APPLICATIONS Automobiles: Beam alert signals can be directly propagated from an announcement device in the dashboard to the driver. Retail sales: Provide targeted advertising directly at the point of purchase. Safety officials: Portable audio spotlighting devices for communicating with a specific person in a crowd of people.
Cont… Public announcement: Highly focused announcement in noisy environments such subways, airports, amusement parks, traffic intersections etc. Emergency rescue: Rescuers can communicate with endangered people far from reach. 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.
Cont… Museums: Audio spotlight can be used to describe about a particular object only to a person standing in front of it. Military applications: Ship-to-ship communication and shipboard announcements. Audio/Video conferring: Project the audio from a conference in 4 different languages, from a single central device without the need for headphones. Sound bullets: Jack the sound level 50 times the human threshold of pain, and an offshoot of audio spotlighting sound technology becomes a non-lethal weapon.
FUTURE OF AUDIO SPOTLIGHTING • 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 think their relationship with sound. Audio spotlighting really “put sound where you want”.
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. • Audio spotlighting system is going to shape the future of sound and will serve our ears with magical experience. • So we can conclude- Audio Spotlighting really “put sound where you want it” and will be • “A REAL BOON TO THE FUTURE.”
BIBLIOGRAPHY • F. Joseph Pompei: The use of airborne ultrasonics for generating audible sound beams. • www.silentsound.co.za – Silent sound. • www.wikipedia.org - Sound from Ultrasound. • www.howstuffworks.com • www.holosonics.com • Electronics For You – Vol. 40 January 2008.