A

SEMINAR REPORT

ON

HYPERSONIC SYSTEMS

Bachelor of Technology

In

Electronics & Communication

Engineering

Submitted to: Submitted by:

Dr. A. K. Gautam Amit Sati

Associate Professor Roll No-04

EEED, GBPEC ECE, IV Year

Pauri, Garhwal GBPEC, Pauri, Garhwal

PREFACE

This seminar is based on one of the latest trends in electronics, ‘HYPERSONIC

SYSTEMS’. It 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. The ultra sound beam acts as an airborne speaker and as the beam moves

through the air gradual distortion takes place in a predictable way due to the property of non-

linearity of air. This gives rise to audible components that can be accurately predicted and

precisely controlled. Joseph Pompei’s Holosonic Research Labs invented the Audio Spotlight

that is made of a sound processor, an amplifier and the transducer. The American Technology

Corporation developed the Hyper Sonic Sound-based Directed Audio Sound System. Both use

ultrasound based solutions to beam sound into a focused beam.

ACKNOWLEDGEMENT

I would like to thank Dr. Y Singh, Professor, HOD ECE Department for providing us this

valuable opportunity of presenting the seminar on latest trends in electronics and communication

which has not only enhanced my knowledge about the subject but also increased my confidence

level.

I would like to convey my special thanks to Dr. A.K Gautam, Associate Professor, EEE

Department for his valuable guidance and motivation. I express my sincere gratitude to Mr.

Manoj Kumar and Mr. Balraj for their co-operation.

I would also like to extend my cordial gratitude and regard to all my friends and

colleagues for their constant help and support. I am sincerely thankful to everyone who has given

me a part of his or her precious time for this seminar.

CONTENTS

1. INTRODUCTION

2. TECHNICAL OVERVIEW

2.1 The working

2.2 HSS systems

2.3 Non linearity property of air

3. ARCHITECTURE

3.1 Components of the system

4. BASIC BENEFITS

5. APPLICATIONS

6. CONCLUSION

7. REFERENCES

1. INTRODUCTION

Hyper Sonic Sound Systems (HSS) is a pioneering sound-generation technology that

broadcasts your message directly to your intended audience. In contrast to conventional

loudspeakers, HSS technology uses a directional ultrasonic column to produce sound exactly

where you want it. Sound does not spread to the sides or rear of an HSS unit, eliminating the

problem of uncomfortable and unwanted noise pollution produced by conventional speakers.

Sound is directed only where it is intended to go. Visualize two people standing four feet

apart at an art exhibit. One patron listens to a biography of a sculpture artist, while the other

contemplates a painting in complete silence! HSS is like handing someone a set of head

phones. By focusing sound in a tight column, HSS allows you to restrict sound to a specific

area without imposing on nearby speaker focused on the area in front of only directory users

to hear the corresponding audio.

Hypersonic Sound (HSS) is the term used to describe the process by which audible

sound waves can be produced using ultrasonic sound waves that are free from non-linearity.

The first attempts at hypersonic sound were made in the 1960’s using underwater sonar. In

the 1970’s it was proven that mathematically HSS could be produced in air, but by the

1980’s the technology was abandoned because of problems with distortion. In the late 1990’s

HSS was again researched because of advances in sound production technology and in 1998

the first working, commercial prototypes were made under the name “Audio Spotlight”.

The advantage of using ultrasonic sound is that sound transmissions can be focused into a

narrow, far-reaching beam that resists diffusion and attenuation; therefore, the beam can be

transmitted over greater distances with pinpoint accuracy. Additionally, this sound beam can

be targeted to only a single object or person, leaving the surrounding environment free of

noise pollution. Already, this technology is being put to use in the advertising and automobile

industries, and the United States military.

First, it is important to understand what a sound wave is. A sound wave is a series of

alternating high (condensation) and low (rarefaction) pressures created by some object

disturbing the environment through which the sound wave is traveling. This pressure wave,

then, is received by the eardrum which converts it through the inner ear into an electric signal

which the brain can process. The key thing to recognize in the case of hypersonic sound is

that each of these small pressure changes is a different micro-environment; the small portions

which are low-pressure have different densities (atmospheric density is related to pressure)

than those that are high-pressure. This is extremely important to note when dealing with the

transmission of a sound wave across distances.

Next, it is important to understand the terms diffusion and attenuation, which describe the

behavior of a sound wave over time. Diffusion is the process by which a sound wave expands

outward, and attenuation is the process by which a sound’s intensity diminishes. These two

characteristics of a sound wave are very interrelated; as a sound wave expands and increases

its area occupied, its intensity (which is inversely proportional to area occupied) decreases.

Additionally, a sound wave’s absorption into the surrounding environment as well as its

reflection off of objects and particles in the environment decreases its intensity and thus

contributes significantly to its attenuation.

Next, it is important to understand what it means to be non-linear and how or why a

sound wave is non-linear. Non-linearity simply means that as the wave advances through the

environment and time elapses, the conditions of the environment in which the wave exists do

not remain constant. Explaining how or why a sound wave is non-linear is a little more

complicated and requires the piecing-together of some facts which have already been noted.

Because a wave’s frequency depends on the speed of sound, and the speed of sound depends

on the density of the environment through which the wave is traveling, and the density of a

fluid (fluids are gasses and liquids) environment depends on the pressure—which is

fluctuating due to the nature of the wave—of the fluid, a wave’s frequency depends greatly,

although transitively, on the pressure of the fluid. As a wave moves through various

pressures, its frequency and speed change. Because the wave’s speed changes, the rate of

diffusion changes as a result of its rate of expansion changing. Because of both the rate of

diffusion changing, and because of the amount of particles to reflect off of (because of the

compression and rarefaction, where lower densities have fewer particles and vice-versa)

changing, the rate of attenuation changes. All of these factors are even further affected as the

sound wave travels outwards because of the diminished intensity and conversely the

diminished compression, rarefaction, attenuation, and diffusion. Thus, a sound wave is non-

linear both in small segments (from one micro-environment to the next) and as an entire

segment (as its intensity diminishes from the source at point A to the target at point B).

2. TECHNICAL OVERVIEW

The HSS Directional Audio System can operate in Direct Mode, a clear line of approach

from the HSS unit to the target listener, and in Virtual Mode, projecting sound onto a sign,

display or other object creating a Virtual Speaker.

Direct Mode assumes that the listener will be in a direct path in front of the HSS device.

He or she will hear the audible sound as the sound column passes by their head. The sound will

continue to travel past them until it either strikes a surface or is absorbed by the air (over a long

distance). A number of things can happen when a sound wave strikes a surface depending on the

surface itself. If the surface is flat and hard (e.g. a mirror or plaster board), the sound will reflect

from the surface. Some energy will be lost, but some of the sound will be reflected back into the

environment. The angle at which the sound strikes the surface will equal the angle at which it

will reflect (assuming a perfect reflector). Of course, there is no perfect reflector so some amount

of the sound will scatter back into the entire area, while the loudest portion will follow the

refection path. If the surface is absorptive at the proper frequencies, the surface will contain the

sound within the surface and little sound will be directed back into the environment. The last

alternative is to make the surface diffusive. If you diffuse the reflection you essentially reflect it

back into the room in all directions. Therefore, no single reflection is louder than all the rest.

One of the great benefits of HSS is the fact that we can now predict where the sound will

strike a surface (first reflection) and treat that surface accordingly. Since traditional loudspeakers

emit sound in all directions, the sound always sounds like it is coming the speaker device

because no matter where you are in the room, the first sound you hear is actually coming directly

at you from the speaker. Now, with HSS, we only have the one column of sound to deal with.

1) REFLECT IT: Angle the HSS device correctly so that the first reflection is directed

where you want it to go. For example, if you don’t want to hear the first reflection, direct it up

into the ceiling, or direct it into an absorptive surface someplace else in the room, etc. Also

remember that sound does dissipate over distance. Therefore, the farther you can make the

reflection travel, the lower it will be in volume when you hear it again. A good example would

be an overhead HSS unit directed down towards the floor with the first reflection going back up

into the ceiling. If the ceiling were 50 ft. away, the reflected sound would have to travel 50 ft. up

and 50 ft. back down before you would hear it again. It may be completely inaudible by that time

depending on how loud it was when it started, the composition of the ceiling, and ambient sound

level.

2) ABSORB IT: Make the surface struck by the first sound reflection highly absorptive.

The better the absorber, the lower the reflected energy. Carpet, for example, is a very poor

absorber. It will absorb some of the highest sound frequencies, but will reflect the remainder.

Some office wall panels are somewhat better, but still they will reflect the majority of the energy.

A local acoustical technician can provide you with the most appropriate absorption

material for the individual installation.

3) DIFFUSE IT: Make the surface multi-layered and multi- dimensional. The more

irregular the surface, the better the diffusion.

HSS can transform signs, placards, and surfaces into Virtual Speakers. Virtual Mode

applications allow units to be placed without cabinet or hardware at the desired sound location.

By projecting sound with an HSS unit, a simple display sign can act as a speaker without wiring

or changing the sign’s appearance. You can project HSS sound to specific end caps or aisle

displays or send sound across the room, without uncomfortable and unwanted volume from

loudspeakers. HSS can turn a wall into an information sound center by adding sound to coupon

panels and directional signage to increase interest.

Imagine:

Introducing a new product and telling customers how to use it at the store display with the

audio message heard only by those standing in front of the display.

Museums, amusement parks, theme parks, or zoos with display-point audio that provides

directions or a narrative about displays or exhibits without the need for conventional headphones.

Providing a section for the hearing impaired at public assemblies, in churches, and in

schools where sound can be enhanced without disruption to other attendees.

Computer operators in an office of cubicles with HSS units placed overhead directing

sound at each individual with no disturbance to coworkers.

Display booths at trade show that direct sound only to those in or in front of the booth,

keeping noise levels to a minimum.

Projecting the audio from an audio/video conference, in four different languages from a

single central device, reaching the intended parties without headphones.

Safety warnings that penetrate general noise in heavy equipment staging areas, rental sites, or

repair yards so that it can be heard by those in risk areas.

Signaling, alerting, and informing specific c individuals in a grocery aisle, waiting room,

or lobby.

Use of the HSS unit to add audio to an ATM with only the customers actually at the

ATM able to hear the message.

All this is now possible with the new hypersonic sound systems.

The unique technical characteristics of HSS offer superior control of sound. HSS creates

new opportunities for designers to implement and use sound as never before. Architects now

have the ability to integrate sound into designs with exciting control of placement. With the HSS

Virtual Mode capability, sound can be added without having to place a loudspeaker where the

sound is needed. Audio engineers will find that HSS is applicable in any situation where it is

desirable to limit the ability to hear sound to a defined space. Since HSS delivers sound

precisely, less volume is necessary to project sound where it is needed; HSS does not inflict

excessive sound pressure at one point to carry the sound to the desired place. HSS can create

virtual loudspeakers, so that sound appears to be coming from points where it would be

impractical or impossible to place a loudspeaker. Hypersonic Sound is a paradigm shift in sound

production based on solid principles of physics.

The human ear is sensitive to frequencies from 20 Hz to 20,000 Hz (the "audio" range),

and can detect the vibration amplitudes that are comparable in size to a hydrogen atom. If the

range of human hearing is expressed as a percentage of shifts from the lowest audible frequency

to the highest, it spans a range of 100,000%. No single loudspeaker element can operate

efficiently or uniformly over this range of frequencies. In order to deal with this speaker

manufacturers carve the audio spectrum into smaller sections. This requires multiple transducers

and crossovers to create a 'higher fidelity' system with current technology. Using a technique of

multiplying audible frequencies upwards and superimposing them on a "carrier" of say, 200,000

cycles the required frequency shift for a transducer would be only 10%. Building a transducer

that only needs to produce waves uniformly over only a 10% frequency range. For example, if a

loudspeaker only needed to operate from 1000 to 1100 Hz (10%), an almost perfect transducer

could be designed an almost perfect transducer could be designed.

2.1 The working

Hyper Sonic Sound technology creates audible sound from the interaction of

two high-frequency signals that are themselves inaudible. A reference signal is held constant at

200 kHz and a variable signal which ranges from 200.020 kHz to 220 kHz are the signals used.

The reference signal combines with variable signal to produce audible signal in the air whose

frequency is equal to the difference between the variable and reference frequencies. As an

example to produce a sound of 263 Hz, the variable signal is made to 200.263 kHz. These

ultrasonic frequencies are inaudible by themselves. However, the interaction of the air and

ultrasonic frequencies creates audible sounds that can be heard along a column. This audible

acoustical sound wave is caused when the air down-converts the ultrasonic frequencies to the

lower frequency spectrum that humans can hear. The basic operating principal of HSS uses a

property of air known as "non-linearity". A normal sound wave (like someone talking) is a small

pressure wave that travels through the air. As the pressure goes up and down, the "nonlinear"

nature of the air itself causes the sound waves to be changed slightly. If you change the sound

waves, new sounds (frequencies) are formed within the wave. Therefore, if we know how the air

affects the sound waves, we can predict exactly what new frequencies (sounds) will be added

into the sufficient volume to cause the air to create these new frequencies.

Since we cannot hear the ultrasonic sound, we only hear the new sounds that are formed

by the non-linear action of the air. Since the audible sound is produced inside the column of

ultrasonic frequencies (which is highly directional), an important by-product of this is that the

audible sound can be tightly focused in any direction within the listening environment. This

provides outstanding edibility in placing the sound exactly where you want it and substantially

eliminating sound in all other areas. The directionality of the HSS system is unsurpassed, with

the added benefit of long projection distances and retention of intelligibility. Getting sound right

where it is wanted eliminates having to use high sound pressure levels to get sound to “carry” to

distant points.

2.2 HSS systems

A Hyper Sonic Sound system consists of an audio program source such as a CD player or

microphone, an HSS signal processor, and an ultrasonic emitter or transducer that is powered by

an ultrasonic amplifier. The music or voice from the audio source is sent to an electronic signal

processor circuit where equalization, dynamic range control, distortion control, and precise

modulation are performed to produce a composite ultrasonic wave. The wave form is converted

to a highly complex ultrasonic signal by the signal processor before being amplified. The patent

pending ModAmp™ technology is used to produce the compact and lightweight

Modulation/Amplifier portions of HSS. This amplified ultrasonic signal is sent to the emitter and

emitted into the air to produce a column of ultrasonic sound that is subsequently converted to

highly directional audible sound within the air column. Since the ultrasonic energy is highly

directional, it forms a virtual column of sound directly in front of the emitter, much like the light

from a flashlight. All along that column of ultrasonic sound, the air is creating new sounds (the

sound that we originally converted to an ultrasonic wave). Since the sound that we hear is

created right in the column of ultrasonic energy, it does not spread in all directions like the sound

from a conventional loudspeaker; instead it stays locked tightly inside the column of ultrasonic

energy. In order to hear the sound, your ears must be in line with the column of ultrasound, or,

you can hear the sound after it reflects off a hard surface. For example, if you point the ultrasonic

emitter toward a wall, you will only hear the audible sound after it has reflected off the wall. This

is similar to shining a flashlight at a wall in a dark room. You do not see the light from the

flashlight; you only see the spot of light on the wall. HSS works the same way, except instead of

seeing the spot of light on the wall; you hear the "spot" of sound reflected from the wall. For

stereo, a separate ultrasonic emitter is required for each channel of audio, one for the left channel

and one for the right channel.

2.3 Non linearity property of air

When two sound sources are positioned relatively closely together and are of a sufficiently high

intensity, two new tones appear: a tone lower than either of the two original ones and a tone

which is higher than the original two. There are now four tones where before there were only

two. It can be demonstrated mathematically that the two new tones correspond to the sum and the

difference of the two original ones, which we refer to as combination tones.

For example, if you were to emit 200,000 Hz and 201,000 Hz into the air, with sufficient

energy to produce a sum and difference tone, you would produce the sum - 401,000 Hz - and the

difference - 1,000 Hz, which is in the range of human hearing.

The HSS concept originates from this theory of combination tones, a phenomenon known

in music for the past 200 years as "Tartan tones." It was long believed that Tartan Tones were a

form of beats because their frequency equals the calculated beat frequency. However, it was

Hermann von Helmholtz (1821-1894) who completely re-ordered the thinking on these tones. By

reporting that he could also hear summation tones (whose frequency was the sum rather than the

difference of the two fundamental tones) Helmholtz demonstrated that the phenomenon had to

result from a non-linearity. Could a method be found today to utilize this non-linearity of air

molecules in a manner similar to the non-linearity of an electronic mixer circuit?

In theory, the principle appears quite simple. Yet, until now, no one has succeeded in

making it work. Nobody has been successful in producing useful levels of sound output in this

difference frequency range. ATC ,the makers of the Hyper Sound Systems thinks that better

audio can be created with a process that they call acoustic heterodyning - mixing signals

together to create new ones - in a process analogous to what virtually every radio receiver uses

today.

Mix two signals in a nonlinear medium and you'll end up with four - two at the original

frequencies, a third at a new frequency that is equal to the sum of the two signals (the sum

frequency) and a fourth at a frequency equal to the difference of the original two signals (the

difference frequency).

Radio receivers use heterodyning to make the signals more manageable - the signal is

converted to a lower frequency (called the intermediate frequency, or IF) by being mixed with a

local oscillator. This allows greater and more consistent amplification of the desired signal

because the amplification circuitry can be optimized for only the IF instead of a wide range of

frequencies.

What makes acoustic heterodyning possible is that air molecules behave nonlinearly - when

sound has a high enough amplitude, the restoring force on the air molecule varies as the square

of its displacement from equilibrium - so that mixing can occur. Take an ultrasonic transducer,

feed it the right signals, they'll mix, and you'll hear the difference frequency. (The original

signals and the sum frequency are outside the range of hearing.)

Acoustic heterodyning can be created by a single transducer or by a pair of transducers. A

single transducer would be fed a signal at a "carrier frequency" and a second signal that would

provide the desired (audible) difference frequencies when mixed with the carrier. If a pair of

transducers was used, one would operate at the carrier frequency and the second at a frequency

required producing the desired output. If the carrier frequency of the transducer were 200 kHz,

an upward swing of 20 kHz - or just 10 percent - would cover the entire audio range. In theory,

this should result in a response that is virtually flat across the audio range - something that no

speaker could hope to match. Other benefits include extremely high efficiency when compared

with traditional speakers, and - since the sound seems to come from a single point in space -

perfect phase coherency.

The audio created by acoustic heterodyning is extremely directional, due to the high

frequency of the ultrasonic carrier. In a demonstration of the technology, we could "shine" the

transducer at a wall, and the sound would seem to emanate from there just as if we had hit it with

a flashlight beam.

This directionality could be used in a movie theater by generating ultrasounds with separate

transducers and swiveling the transducers to change the point where the ultrasound beams would

meet, making sound hover or travel over the heads of viewers. Giving directors the ability to put

sound exactly where they want it adds a whole new dimension to surround sound. Although

acoustic heterodyning has extraordinary promise, don't throw your speakers on the trash heap

just yet. In our demonstration, the transducer was only able to create sound equivalent to a small

AM transistor radio. It completely lacked a bottom end.

ATC is now working with Carver Corp. to improve the technology's performance to make

this audio reproduction revolution a reality. Expect to see some commercial products within a

few years.

It's difficult for any conventional speaker to reproduce the entire spectrum of human

hearing, which extends from deep bass notes at 20 hertz (cycles per sound) to shrill 20,000-hz

tones. Speaker materials that can make rich bass sounds can't accurately handle high notes.

Consequently, speaker boxes typically house two or more speakers, each specializing in narrow

tonal ranges. Now, all these complexities go out the window. Norris' little Hyper Sonic speakers

aren't troubled by the breadth of human hearing because they operate in a different realm--the

ultrasonic. One of the two ultrasonic signals that produce audible sound as a byproduct is a

constant 200,000-hz frequency. It's mixed with a second signal that varies from 200,020 Hz to

220,000 Hz. Subtract one from the other, and the resulting tones run the audible gamut.

3. ARCHITECTURE

Hypersonic sound uses a property of air known as ‘nonlinearity’. A normal sound wave is

a small pressure wave that travels through the air. As the pressure goes up and down, the

‘nonlinear’ nature of the air itself slightly changes the sound wave. If there is change in a sound

wave, new sounds are formed within the wave. Therefore if we know how the air affects the

sound waves, we can predict exactly what new frequencies (sounds) will be added into the sound

wave by the air itself. An ultrasonic sound wave (beyond the range of human hearing) can be

sent into the air with sufficient volume to cause the air to create these new frequencies. Since we

cannot hear the ultrasonic sound, we only hear the new sounds that are formed by the nonlinear

action of the air.

Hypersonic sound technology precisely provides linear frequency response with virtually

no distortion associated with conventional speakers. Physical size no longer defines fidelity. The

faithful reproduction of sound is freed from bulky enclosures. There are no woofers, tweeters or

crossovers.

An important byproduct of this technique is that sound may be projected to just about any

desired point in the listening environment. This provides outstanding flexibility, while allowing

for an unprecedented manipulation of the sound’s source point.

Hypersonic technology is analogous to the beam of light from a flashlight. If you stand to

the side or behind the light, you can ‘see’ the light only when it strikes a surface. This technology

is similar in that you can direct the ultrasonic emitter towards a hard surface, a wall for instance,

and the listener perceives the sound as coming from the spot of the wall.

3.1 Components of the system

Power supply: Like all electronics, the hypersonic sound system works off dc voltage. A

universal switch mode power supply is standardized at 48V for the ultrasonic power amplifier. In

addition, low voltage is used for the microcontroller unit and other process management.

Audio signal processing: The audio signal is sent to an electronic signal processor circuit where

equalization, dynamic range control and precise modulation are performed to produce a

composite ultrasonic waveform. This amplified ultrasonic signal is sent to the emitter, which

produces a column of ultrasonic sound that is subsequently converted into highly directional

audible sound within the air column.

Since ultrasound is highly directional, the audio sound placement is precise. At the heart

of the system is a high precision oscillator in the ultrasonic region with a variable frequency

ranging from 40 to 50 kHz.

Dynamic double side-band (DSB) modulator: In order to convert the source program material

into ultrasonic signals, a modulation scheme is required. In addition, error correction is needed to

reduce distortion without loss of efficiency. The goal, of course, is to produce audio in the most

efficient manner while maintaining acceptably low distortion levels.

We know that for a DSB system, the modulation index can be reduced to decrease

distortion, but this comes at the cost of reduced conversion efficiency. A square-rooted envelope

reference with zero bandwidth distortion, the basis of the proprietary parametric processor,

handles the situation effectively.

Ultrasonic modulation amplifier: High efficiency ultrasonic power amplifier amplifies the

carrier frequency with correlation, responds to reactive power regeneration and matches the

impedance of the integrated transducers.

Microcontroller: A dedicated microcontroller circuit takes care of the functional management

of the system. In the future version, it is expected that the whole process like functional

management of the system, signal processing, double side-band modulation and even switch

mode power supply would be effectively taken care of by a single embedded IC.

Transducer technology: The most active piezo film is polyvinylidene difluoride. This film is

commonly used in many industrial and chemical applications.

In order to be useful for ultrasonic transduction, the raw film must be polarized or

activated. This is done by one of the two methods. One method yields a ‘uniaxial’ film that

changes length along one axis when an electric field is applied through it. The other method

yields a ‘biaxial’ film that shrinks/expands along two axes. Finally, the film needs to have a

conductive electrode material applied to both sides in order to achieve a uniform electric field

through it.

Piezoelectric films operate as transducers through the expansion and contraction of ‘X’ or

‘Y’ axes of the film surface. For use as a hypersonic sound emitter, the film is to be curved or

distended. The curving results in expansion and contraction in the ‘Z’ axis, generating acoustic

output.

The music or voice from the audio source is converted into a highly complex ultrasonic

signal by the signal processor before being amplified and emitted into the air by the transducer.

Since the ultrasonic energy is highly directional, it forms a virtual column of sound directly in

front of the emitter, much like the light from a flashlight.

Specifications of a typical HSS

SOUND BEAM PROCESSOR/AMPLIFIER

1. Worldwide power input standard

2. Standard chassis 6.76”/171mm (w) x 2.26”/57mm (h)x 11”/280mm (d), optional rack

mount kit

3. Audio input: balanced XLR, 1/4” and RCA (with BTW adapter) Custom

configurations available e.g. Multichannel

AUDIO SPOTLIGHT TRANSDUCER

1. 17.5”/445mm diameter, 1/2”/12.7mm thick, 4lbs/1.82kg

2. Wall, overhead or flush mounting

3. Black cloth covers standard, other colours available

4. Audio output: 100dB max

5. ~1% THD typical @ 1 kHz

6. Usable range: 20m

7. Audibility to 200m

8. Optional integrated laser aimer 13”/ 330.2mm and 24”/ 609.6mm diameter also

available

9. Fully CE compliant

10. Fully real time sound reproduction - no processing lag

4.BASIC BENEFITS

1. Small Size

Not only has the conventional speaker's crossover network and enclosure been

eliminated, but HSS' ultra-small radiating ultrasonic emitter is so small and light-weight

that the inertial considerations ordinarily associated with traditional direct-radiation

speakers are virtually non-existent. (And so is just about everything else associated with

the conventional speaker: the voice coil and support structure normally used to attach the

moving cone in place.)

2. Point Source

The ability to produce the entire audible spectrum of frequencies from a single

point source has been the goal of transducer engineers for the past 50 years. The

improvement in phase response, time alignment, and frequency response becomes

obvious.

3. Performance

Preliminary testing of the ATC proof-of-concept prototype shows the HSS

technology should have the potential for the following performance specifications:

a. Dynamic range up 120 dB at all frequencies

b. No crossover networks

c. Precise phase and time alignment

d. Room interaction reduced up to 50 dB

e. Frequency response from below 10 Hz to 30 kHz

5. APPLICATIONS

The applications are many, from

targeted advertising to virtual rear-channel

speakers. The key is frequency: The

ultrasonic speakers create sound at more than

20,000 cycles per second, a rate high enough

to keep in a focused beam and beyond the

range of human hearing. As the waves disperse, properties of the air cause them to break into

three additional frequencies, one of which you can hear. This sonic frequency gets trapped within

the other three, so it stays within the ultrasonic cone to create directional audio. Step into the

beam and you hear the sound as if it were being generated inside your head. Reflect it off a

surface and it sounds like it originated there. At 30,000 cycles, the sound can travel 150 yards

without any distortion or loss of volume. Here's a look at a few of the first applications.

1. Virtual Home Theater

about 3.1-speaker Dolby Digital

sound? With Hypersonic, you can

eliminate the rear speakers in a 5.1

setup. Instead, you create virtual

speakers on the back wall.

2. Targeted Advertising

"Get $1 off your next purchase of

Wearies," you might hear at the

supermarket. Take a step to the right,

and a different voice hawks Crunch

Berries.

3. Sound Bullets

Jack the sound level up to 145

decibels, or 50 times the human

threshold of pain, and an offshoot of

hypersonic sound technology becomes

a non lethal weapon.

4. Moving movie voices.

For heightened realism, an array of directional speakers could follow actors as they walk across

the silver screen, the sound shifting subtly as they turn their heads.

5. Pointed Messages

"You're out too far," a lifeguard could yell into his hypersonic megaphone, disturbing none of the

bathing beauties nearby.

6. Discreet Speakerphone

With its adjustable reach, a hypersonic speakerphone wouldn't disturb your cube neighbors.

The following contains a brief list of other uses made possible by HSS:

• Museums - describe each exhibit to only the person standing in front of it

• Automobiles - HSS announcement device in the dash to “beam” alert signals directly to the

driver

• Audio/Video Conferencing - project the audio from a conference in four different languages,

from a single central device, without the need for headphones.

• Paging Systems - direct the announcement to the specific area of interest

• Retail Sales - provide targeted advertising directly at the point of purchase

• Drive Through Ordering – intelligible Communications directly with an automobile driver

without bothering the surrounding neighbors

Besides consumer electronics, the entertainment industry is expected to be fundamentally

influenced by this development. In a movie theater, sound can be made to emanate directly from

an actor's mouth on the screen. Special effects will no longer be limited to the capability of

loudspeakers positioned around the auditorium.

You might want to project concert sound throughout an audience instead of using huge

speaker stacks in front. A small table radio might project sound around an entire room. Why not

equip your back yard with tightly focused HSS emitters to project sound all around your yard for

that next pool party.

Until now, it has been difficult for a hearing aid--regardless of price--to reproduce the

entire audio spectrum. This no longer need be the case. With HSS, hearing aids may also shrink

further in size. Virtual reality, in large-scale applications, has been brought another step closer.

No longer is the quality of the sound related to the size or type of a speaker's enclosure.

Everywhere and anywhere a speaker is in use today--ships, aircraft, hospitals, automobiles--the

HSS technology can replace the bulkier, inefficient speakers, and provide far better results than

we have ever heard. Truly, this is a quantum leap, a paradigm shift.

6. CONCLUSION

As a conclusive remark, this paper discussed about the coming of the Hypersonic Speaker

Systems which are yet not implemented, but is a real promising innovation which may be applied

in our everyday life and will revolutionize the sound technology. This paper discussed about the

invention, the inventor, the motive behind the invention, etc. Also discussed about how

hypersonic sound is created and how the hypersonic system works, which method is used, etc.

What the advantages of hypersonic speakers are, over conventional systems. We also discussed

about their wide forms of applications.

7. REFERENCES

• http://www.atcsd.com

• http://www.usatoday.com

• http://www.acoustic.org

• http://www.m-media.com

• http://www.thinkdigit.com

• http://www.holosonics.com

• http://www.spie.org

• http://www.howstuffworks.com

• http://www.abcNEWS.com