## måndag 27 maj 2013

### uppdate my email

Blogg update 27/5-13

uppdate my email

or
jan248@live.se

+46721881571
0721881571

Richard

### Blogg 20130527 update blogg

Blogg 20130527 update blogg

Änteligen klar med copy från andra hemsidan.
Nu är det dags att uppdatera denna blogg.

Finally ready whith copy from my old homepage.
Now its time to update this blogg.

Richard

### 04042011 Blogginlägg

04042011 Blogginlägg

04042011 Blog Post
Negative, and finally, I can figure out why.
Excerpt from August 5, 2010 and

04042011 Blogginlägg
Negativt, och slutligen, jag kan räkna ut varför.
Utdrag ur 5 Aug 2010 och
Blogg inlägg Human right 5 Aug 2010

Rights and human value, I also have one.
I can not become it, I've struggled with about anything in over 3000 days. And they have the VOICE thwarted over a thousand attempts and ruined them with cowardice and ignorance from people every time.
Because I've actually where professionals sometimes and not won.
I ought to have done it sometime.
Thus, it is, and that it goes not over.
Richard

Rättigheter och mänskligt värde, också jag har ett.
Jag kan inte bli den, jag har kämpat med vadsomhellst i över 3000dagar. Och de har med VOICE motarbetat över tusen försök och förstört dem med feghet och okunnighet från befolkningen varje gång.
För jag har faktiskt vart proffs ibland och inte vunnit.
Jag borde ju klarat det nån gång.
Det är alltså de, och det det går inte över.
Richard
Blogg inlägg 5 aug 2010

My deal should apply, return my deal where they should be.
Richard

Mina deal bör gälla, lägg tillbaka mina deal där de ska vara.
Richard
Kommentarer(49)
2011-04-04 03:32

### Audiospotlight by holosonic application Disney - Holosonic Audio Spotlight

Audiospotlight by holosonic application Disney - Holosonic Audio Spotlight http://www.holosonics.com/a_museums.html
Audio Spotlight Sound Beam Systems Installed in General Motors Display at Walt Disney's Epcot

June 30, 2004
Press Release

Holosonics, the world leader in directional acoustic technology, is pleased to announce a new installation of its Audio Spotlight systems at Walt Disney's Epcot Center. The Audio Spotlight, invented at the Massachusetts Institute of Technology, is the first and only system in the world that creates high-quality sound in narrow beams - much like the light from a flashlight. The patented Audio Spotlight systems are installed in the Innoventions exhibit, which, according to Disney, highlights "some of the newest time-saving and technological wonders for our new millennium with products being used in the home and around the world."
Within Innoventions, General Motors is exhibiting the Juno, a state-of-the-art vehicle with a sound system consisting of four Audio Spotlight discs - one over each seat. This unique technology allows each passenger in the vehicle to hear their own sound - and no one else's. "The parents in the front seat aren't distracted by the movies and video games in the back seat - each parent can even choose what they want to hear," says Dr. F. Joseph Pompei, inventor of the technology. "This application builds on knowledge we had during our work with DaimlerChrysler beginning in 2001. The Audio Spotlight technology has made great strides in the past few years, and General Motors deserves credit for working hard to show off how far we've come."
The Audio Spotlight technology is also used in Innoventions to wow the crowd with its unique focused acoustical beams - sound literally flies by the crowd's faces, and travels around the room, often resulting in dropped-jaws and gasps from the crowd.
While in-car applications are still under development, Audio Spotlight technology is already commercially available, and is the choice of the world's top museums and exhibitors for localizing sound to specific areas in their galleries, without creating background noise. Installations include the Smithsonian Institution, the Boston Museum of Science, Chicago Cultural Center, and the Tate Gallery in London. Many of the world's top corporations, such as Motorola, Time-Warner, Cisco, and Steelcase, are also using Audio Spotlight systems for their stores, showrooms and visitor's centers.

Holosonic Research Labs, Inc., a pioneer in directional acoustics, develops and manufactures the Audio Spotlight® directional sound system. Founded in 1999 by MIT graduate Dr. F. Joseph Pompei, Holosonics' Audio Spotlight technology is used in a wide variety of applications including museums, libraries, offices, reception areas, retail displays, trade shows and retail kiosks. The world's top organizations and companies such as Cisco, Motorola, the Smithsonian Institute, the Tate Modern and Time-Warner use the Audio Spotlight directional sound system to beam sound to their listeners... and preserve the quiet.™
Press inquiries: press@holosonics.com
Epcot® and Disney® are registered trademarks of the Walt Disney Corporation.
Holosonics' Audio Spotlight Makes Quiet Fashionable

Boston Museum of Fine Arts' Exhibit Uses Directional Sound System

August 10, 2007
Press Release

BOSTON, Mass. - Rhythmic techno and heart-pumping drum-and-bass are not music genres typically associated with fine art exhibits; however, using the Audio Spotlight directional sound system from Holosonic Research Labs, Inc., Boston's Museum of Fine Arts (MFA) was able to incorporate this "runway" music into its "Fashion Show: Paris Collections" exhibit without intruding on the peaceful museum ambiance.
The show, which opened in November, highlighted 10 designers' collections - designers with very different aesthetics and visions. Holosonics' Audio Spotlight Directional Sound System established a unique soundscape to distinguish each collection.
"Fashion Show: Paris Collections" featured runway-style displays highlighting 10 pieces from each designer-an audio/video recording of the actual runway show and accompanying explanatory plaques bring the clothing to life. But Yohji Yamamoto's deconstructed, menswear-inspired pieces and Viktor & Rolf's rigid yet feminine dresses and jackets needed the audio aspect - the runway music - that represented them to remain as focused as their plastic mannequins. The Audio Spotlight systems, located directly above each designer's "runway," deliver targeted sound to those viewing that particular collection, and no one else.
The 1/2 inch thin, circular speaker discs create an ultrasonic signal that generates targeted sound only audible to those standing directly within the acoustic beam. The directional sound of the Audio Spotlight system enabled the MFA to include all 10 designers' collections, and play their individual soundtracks, in one gallery without crossover noise.
"Audio Spotlight delivers crisp music at an audible volume in only one direction and one defined area," explains Joseph Pompei, president of Holosonic Research Labs, Inc. "In a true homage to the craftsmanship and the theatrics of high fashion, the MFA was able to spotlight these designers' collections using both sight and sound."

Holosonic Research Labs, Inc., a pioneer in directional acoustics, develops and manufactures the Audio Spotlight® directional sound system. Founded in 1999 by MIT graduate Dr. F. Joseph Pompei, Holosonics' Audio Spotlight technology is used in a wide variety of applications including museums, libraries, offices, reception areas, retail displays, trade shows and retail kiosks. The world's top organizations and companies such as Cisco, Motorola, the Smithsonian Institute, the Tate Modern and Time-Warner use the Audio Spotlight directional sound system to beam sound to their listeners... and preserve the quiet.™
Press inquiries: press@holosonics.com
Kommentarer(9)
2011-03-03 13:59

### 21Feb2011 Blogginlägg

21Feb2011 Entries have fixed with some fun stuff today.
And want to tinker with the website.
I want to be on. You are convicted.
Richard

21Feb2011 BlogginläggHar fixat med lite qul saker idag.
Och vill fixa lite med hemsidan.
Jag vill va på. Du är fälld.
Richard
Kommentarer(38)
2011-02-21 18:39

### 20Feb2011

20Feb2011
20Feb2011

Blog Post
Extract from ...

Blogginlägg
Utdrag ur...
Blogg inlägg 3 sep 2010

Blog posts
In my dreams, it is about Telepath and children.
In my nightmares ...
... called the perpetrators and try on attempted robbery on me ...
... They call themselves by what they are ...
... Pig joker calls himself Markus ...
... Schimpanshittler, Clown calls himself Peter ...
... Psycho, Leech, zany, Telepathaters call themselves Mattias ...
Strange coincidence, but they call themselves so named.
Richard

Blogg inlägg
I mina drömmar står det om Telepath och barn.
I mina mardrömmar...
... kallas de Gärningsmän och försöker sig på rånförsök på mig...
... De kallar sig efter vad de är ...
... Gris, jycklare kallar sig Markus ...
... Schimpanshittler, Clown kallar sig Peter ...
... Psykopat, Blodigel, Pajas, Telepathatare kallar sig Mattias ...
Konstigt sammanträffande, men de kallar sig så med namn.
Richard
Kommentarer(39)
2011-02-20 17:12

### Blogginlägg 20130527

Blogginlägg 20130527
Här ligger 1 inlägg

### Blogginlägg 20130527

Blogginlägg 20130527

Här ligger 1 inlägg

### Blogginlägg 20130527

Blogginlägg 20130527

Här ligger 1 inlägg

### Blogginlägg 20130527

Blogginlägg 20130527

Här ligger 1 inlägg

Richard

### VeriChip's National Rollout Begins in Palm Beach County, Florida

VeriChip's National Rollout Begins in Palm Beach County, Florida
VeriChip's National Rollout Begins in Palm Beach County, Florida
Jacobs Family to Get Chipped'' May 10, 2002
Local hospitals and physicians to participate in initial rollout of VeriChip(TM) and the GVS Registry
PALM BEACH, Fla.--(BUSINESS WIRE)--April 22, 2002-- Sales and registration of VeriChip to begin May 13, 2002
Applied Digital Solutions, Inc. (Nasdaq: ADSX - news), an advanced technology development company, announced today that the Jacobs family will be the first in the world to get chipped''(TM) with VeriChip's personal verification microchip.
The historic chipping'' procedure will take place in the first Authorized VeriChip Center in Palm Beach County, Florida, on May 10, 2002.
VeriChip is a miniaturized, implantable, radio frequency identification device (RFID) that can be used in a variety of security, emergency and healthcare applications. On April 4, 2002, the company announced that it had received written guidance that the U.S. Food and Drug Administration (FDA) does not consider VeriChip's personal verification device to be a regulated medical device, enabling the company to begin sales, marketing and distribution of VeriChip in the United States. The company believes its first-mover advantage will enable it to gain significant market share in the emergency information and verification market that is estimated to exceed $15 billion. Each VeriChip is composed of FDA-accepted materials and contains a unique verification number that can seamlessly integrate to the Global VeriChip Subscriber (GVS) Registry. This Registry program will enable VeriChip subscribers to store pertinent personal verification and healthcare information in the company's secure database. The GVS Registry is hosted and maintained by Digital Angel Corporation's (Amex: DOC - news) state-of-the-art, FDA-compliant operations center in Owings, Maryland. Information provided by the subscriber will be stored in the GVS Registry database. Only information authorized by the subscriber will be available for access via VeriChip's proprietary scanner. Instant access to such vital information as allergies to medications, medical device implants, pre-existing medical conditions and emergency contact numbers could save lives in an emergency and enhance the peace of mind of subscribers and their loved ones. VeriChip System Affiliates such as hospitals, healthcare clinics, search and rescue units, and EMTs will be able to use proprietary VeriChip scanners to read a subscriber's VeriChip and gain access to the subscriber's Registry information if authorized to do so by the subscriber. Scott R. Silverman, President of Applied Digital Solutions, first announced the May 10, 2002, event during a recent interview on MSNBC and said: On May 10th we'll make history with the first-ever chipping' procedure and the launch of VeriChip and the GVS Registry into the U.S. market. We're delighted that we've been able to bring VeriChip's life-enhancing technology to market in record time. We announced VeriChip less than six months ago and now we're about to launch the product into the U.S. market.'' Silverman continued: We're very pleased with the excellent cooperation and excitement we've received from the healthcare community in Palm Beach County. The active involvement of VeriChip System Affiliates like hospitals and EMS units who will use VeriChip proprietary scanners and link into the GVS Registry is critical. In addition, we've identified a well-respected medical practice in Palm Beach County to become the first Authorized VeriChip Center. In conjunction with this Center, we're launching the first ChipMobile(TM) - a state of the art, medically equipped mobile unit that will deliver VeriChip to initial target markets such as elder care centers, critical care facilities and Generation Y events. This initial rollout in Palm Beach County will last until June 30, 2002, at which time we will explore other geographic market opportunities and nationwide distributor alliance programs.'' The historic chipping procedure on May 10th will be followed by a press conference and an invitation-only brunch for business partners and community leaders. During the press conference and the business brunch, Applied Digital executives will unveil more details about VeriChip's rollout plans. About VeriChip(TM) VeriChip, first announced on December 19, 2001, is a miniaturized, implantable, radio frequency identification device (RFID) that can be used in a variety of security, emergency and healthcare applications. On April 4, 2002, the company announced that it had received written guidance that the U.S. Food and Drug Administration (FDA) does not consider VeriChip's personal verification device to be a regulated medical device, enabling the company to begin sales, marketing and distribution of VeriChip in the United States. About the size of a grain of rice, each VeriChip is composed of FDA-accepted materials and contains a unique verification number. That number is captured by briefly passing a proprietary, external scanner over the VeriChip. A small amount of radio frequency energy passes through the skin energizing the dormant VeriChip, which then emits a radio frequency signal transmitting the verification number. VeriChip Corporation is a wholly owned subsidiary of Applied Digital Solutions. About Digital Angel Corporation Digital Angel Corporation (Amex: DOC - news) was formed on March 27, 2002, in a merger between Digital Angel Corporation and Medical Advisory Systems, a global leader in telemedicine that has operated a 24/7, physician-staffed call center in Owings, Maryland, for two decades. Prior to the merger, Digital Angel Corporation was a wholly owned subsidiary of Applied Digital Solutions. Digital Angel(TM) technology represents the first-ever combination of advanced biosensors and Web-enabled wireless telecommunications linked to the Global Positioning System (GPS). By utilizing advanced biosensor capabilities, Digital Angel will be able to monitor key body functions - such as temperature and pulse - and transmit that data, along with accurate emergency location information, to a ground station or monitoring facility. For more information about Digital Angel, visit http://www.digitalangel.net. About Applied Digital Solutions Applied Digital Solutions (Nasdaq: ADSX - news) is an advanced technology development company that focuses on a range of early warning alert, miniaturized power sources and security monitoring systems combined with the comprehensive data management services required to support them. Through its Advanced Technology Group, the company specializes in security-related data collection, value-added data intelligence and complex data delivery systems for a wide variety of end users including commercial operations, government agencies and consumers. For more information, visit the company's website at http://www.adsx.com. Statements about the Company's future expectations, including future revenues and earnings, and all other statements in this press release other than historical facts are forward-looking statements'' within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934, and as that term is defined in the Private Litigation Reform Act of 1995. Such forward-looking statements involve risks and uncertainties and are subject to change at any time, and the Company's actual results could differ materially from expected results. The Company undertakes no obligation to update forward-looking statements to reflect subsequently occurring events or circumstances. Kommentarer(7) 2011-02-14 03:57 ### Microchips of the rich and famous http://home.intekom.com/millennia/worldwatch/science.htm Microchips of the rich and famous Electronic Wire/TNS metimes gun-toting bodyguards, armored limousines and clever disguises just aren't enough. Now the rich and famous of the world are being offered a new kind of protection to keep them from the greedy clutches of ransom-seeking kidnappers: A microchip that will be implanted under their skin. The device is being marketed to the world's richest families as protection against the booming worldwide business in abductions, which has risen by 60 percent in the last eight years, especially in impoverished and corrupt countries like Mexico, Chechnya and the Philippines. The new technology, reported by the Times of London, is a low-power chip that sucks electrical energy from the body itself and--according to the Gen-Etics corporation that makes the things--can be detected by Global Positioning System satellites circling the globe. Designed first by the Israeli spy-masters of the Mossad, Gen-Etics is launching the new "Sky-Eye" chips in Milan, Italy. The company told the Times that it has already stitched the$7,500 gadget into 45 of the world's richest people.
Once a person "wearing" a Sky-Eye chip is abducted, cops and security teams will track his or her location using the satellites and--presumably--send in a commando squad to rescue them. The Sky-Eye is said to have a margin of error of just 150 yards.
But what if the kidnappers decide to tear the thing out themselves? Gen-Etics doesn't have a perfect answer for that question, although they're trying. First, the actual surgery to insert the tiny chip is done under an anesthetic that makes it impossible for the kidnap victim to even remember where it was put in. Second, the thing is so small--just 4 mm by 4 mm, and running on just a few milliamperes of the body's own natural electricity--that it doesn't show up on x-rays.
Kommentarer(15)
2011-02-14 02:39

13feb 2011 - 2

### Redigerat från

Blogg inlägg 24 juli

Blog posts
This is how we constuct and set it up.
We witness the before and after he can get a child as long as he even understand that he could get them.
We witness in now and when, whatever happens.
Blackmailers like we do not.
And he understands her child. With the life he demands and testify.
It's been ten years and it may take a while longer. For me it is important to testify in. I've made it this far and then I can manage for a while towards .
It's actually me who where whih about and created this.
I am the owner of digital and genetic telepathmaterial, files, and developing skills to my program.
United Nations Convention § 1;
European Convention § 1.
The Constitution Act § 18.
And I would have felled them.
Day and night.
Exceeds 5000 visitormanagement
Richard Svanberg

Blogg inlägg
Så här lägger vi det.
Vi vittnar in före och efter han kan få ett barn så länge han ens förstår att han kunde få dem.
Vi vittnar in nu och när, vad som än händer.
Utpressare gillar vi ej.
Och han förstår sitt barn. Med den tillvaron kräver han och vittna.
Det har gått tio år och det kan gå en tid till. För mig är det viktigt och vittna in. Jag har klarat mig så här långt och då klarar jag mig ett tag till.
Det är faktiskt jag som vart med om och skapat det här.
Jag är ägare till digitala och genetiska telepatmaterialet, filer, och utvecklingkunskaper till mitt program.
FN konventionen 1§ ,
EU konventionen 1§.
Regerinsformen  18§.
Och jag vill ha fällt dem.
Dag och natt.
Passerat 5000 visitor
Richard Svanberg
Kommentarer(4)
2011-02-13 18:39

woody norris
What Are Some Woody Norris Successes?
The inventions of Woody Norris run the gamut, encompassingthe worlds of medicine, transportation, entertainment, andelectronics.`
Inventions yet to come will revolutionize additional arenas.
Woody draws on the latest technology as it evolves, combines it with radical new concepts, and then develops exciting new inventions from this blend of technology and vision.
Imminently practical, he is intimately involved in the development of the prototypes and production models of his inventions. He also tracks his products through the manufacturing and marketing processes, all the way to their final marketplace.
 Inventor Wins $500,000 Lemelson-MIT Prize for Revolutionizing Acoustics The$500,000 Lemelson-MIT Prize, largest single cash prize for invention in the United States, is awarded to an individual who demonstrates remarkable inventiveness and creativity, and a proven commitment to inspiring others.  A distinguished panel of scientists, technologists, engineers and entrepreneurs selects the winner.

Kommentarer(0)
2011-02-13 17:26

## Sound from ultrasound

Sound from ultrasound is the name given here to situations when modulated ultrasound can make its carried signal audible without needing a receiver set. This happens when the modulated ultrasound passes through anything which behaves nonlinearly and thus acts intentionally or unintentionally as a demodulator.

## Parametric array

Researchers since the early 1960s have been experimenting with creating directive low-frequency sound from nonlinear interaction of an aimed beam of ultrasound waves produced by a parametric array using heterodyning. Ultrasound has wavelengths much smaller than audible sound and thus can be aimed in a much tighter narrow beam than any traditional audible loudspeaker system.
The first modern device was created in 1998,[1] and is now known by the trademark name "Audio Spotlight", a term first coined in 1983 by the Japanese researchers[2] who abandoned the technology as unfeasible in the mid 1980s.
A transducer can be made to project a narrow beam of modulated ultrasound that is powerful enough (100 to 110 dBSPL) to substantially change the speed of sound in the air that it passes through. The air within the beam behaves nonlinearly and extracts the modulation signal from the ultrasound, resulting in sound that can be heard only along the path of the beam, or that appears to radiate from any surface that the beam strikes. The practical effect of this technology is that a beam of sound can be projected over a long distance to be heard only in a small well-defined area . A listener outside the beam hears nothing. This effect cannot be achieved with conventional loudspeakers, because sound at audible frequencies cannot be focused into such a narrow beam.
There are some criticisms of this approach. Anyone or anything that disrupts the path of the beam will interrupt the progression of the beam, like interrupting the illumination of a spotlight. For this reason, most systems are mounted overhead, like lighting.

## Applications

To aim a sound signal at a particular passer-by without everybody in the area hearing it. In commercial applications it can target sound to a single person without the peripheral sound and related noise that a loudspeaker emits.

### Military and commercial security applications

Military applications have been speculated, such as a "sonic bullet" weapon that aims a highly-directed high-intensity sound wave, causing debilitating pain. However, these devices, such asLRAD, are really just high-powered bullhorns, and contrary to popular misconception, do not use ultrasound at all for sound generation, and instead use traditional loudspeaker elements (tweeters). This type of loudspeaker is unrelated to this article. Wikileaks has published leaked technical specifications for military use of anti-crowd , anti-pirate sound weapons. "Ref"

## History

This technology was originally developed by the US Navy and Soviet Navy for underwater sonarin the mid-1960s, and was briefly investigated by Japanese researchers in the early 1980s, but these efforts were abandoned due to extremely poor sound quality (high distortion) and substantial system cost. These problems went unsolved until a paper published by Dr. F. Joseph Pompei of the Massachusetts Institute of Technology in 1998 (105th AES Conv, Preprint 4853, 1998) fully described a working device that reduced audible distortion essentially to that of a traditional loudspeaker.

## Products

There are currently four known devices which have been marketed that use ultrasound to create an audible "beam" of sound.

### Audio Spotlight

F. Joseph Pompei of MIT developed technology he calls the "Audio Spotlight",[3] and made it commercially available in 2000 by his company Holosonics, which according to their website claims to have sold "thousands" of their "Audio Spotlight" systems. Disney was amongst the first major corporations to adopt it for use at the Epcot Center, and many other application examples are shown on the Holosonics website.[4]

### HyperSonic Sound

Elwood "Woody" Norris, founder and Chairman of American Technology Corporation (ATC), announced he had successfully created a device which achieved ultrasound transmission of sound in 2002. ATC named and trademarked their device as "HyperSonic Sound" (HSS). In December 2002, Popular Science named HyperSonic Sound the best invention of 2002. Norris received the 2005 Lemelson-MIT Prize for his invention of a "hypersonic sound".[5] ATC has abandoned the technology in favor of their large-scale military bullhorn products (LRAD), according to their quarterly reports and executive statements.[6]

### Mitsubishi Electric Engineering Corporation

Mitsubishi apparently offers a sound from ultrasound product named the "MSP-50E"[7] but commercial availability has not been confirmed.

### AudioBeam

The German audio company Sennheiser Electronic once listed their "AudioBeam" product for about \$4,500.[8] There is no indication that the product has been used in any public applications. The product has since been discontinued.[9]

## Literature survey

The first experimental systems were built over 30 years ago, although these first versions only played simple tones. It was not until much later (see above) that the systems were built for practical listening use.

### Experimental ultrasonic nonlinear acoustics

A chronological summary of the experimental approaches taken to examine Audio Spotlight systems in the past will be presented here. At the turn of the millennium working versions of an Audio Spotlight capable of reproducing speech and music could be bought from Holosonics, a company founded on Dr. Pompei's work in the MIT Media Lab.[10]
Related topics were researched almost 40 years earlier in the context of underwater acoustics.
1. The first article[11] consisted of a theoretical formulation of the half pressure angle of the demodulated signal.
2. The second article[12] provided an experimental comparison to the theoretical predictions.
Both articles were supported by the U.S. Office of Naval Research, specifically for the use of the phenomenon for underwater sonar pulses. It should be noted that the goal of these systems was not high directivity per se, but rather higher usable bandwidth of a typically band-limited transducer.
The 1970s saw some activity in experimental airborne systems, both in air[13] and underwater.[14] Again supported by the U.S. Office of Naval Research, the primary aim of the underwater experiments was to determine the range limitations of sonar pulse propagation due to nonlinear distortion. The airborne experiments were aimed at recording quantitative data about the directivity and propagation loss of both the ultrasonic carrier and demodulated waves, rather than developing the capability to reproduce an audio signal.
In 1983 the idea was again revisited experimentally[2] but this time with the firm intent to analyze the use of the system in air to form a more complex base band signal in a highly directional manner. The signal processing used to achieve this was simple DSB-AM with no precompensation, and because of the lack of precompensation applied to the input signal, the THD Total harmonic distortion levels of this system would have probably been satisfactory for speech reproduction, but prohibitive for the reproduction of music. An interesting feature of the experimental set up used in[2] was the use of 547 ultrasonic transducers to produce a 40 kHz ultrasonic sound source of over 130db at 4m, which would demand significant safety considerations.[15][16] Even though this experiment clearly demonstrated the potential to reproduce audio signals using an ultrasonic system, it also showed that the system suffered from heavy distortion, especially when no precompensation was used.

### Theoretical ultrasonic nonlinear acoustics

The equations that govern nonlinear acoustics are quite complicated[17][18] and unfortunately they do not have general analytical solutions. They usually require the use of a computer simulation.[19] However, as early as 1965, Berktay performed an analysis[20] under some simplifying assumptions that allowed the demodulated SPL to be written in terms of the amplitude modulated ultrasonic carrier wave pressure Pc and various physical parameters. Note that the demodulation process is extremely lossy, with a minimum loss in the order of 60dB from the ultrasonic SPL to the audible wave SPL. A precompensation scheme can be based from Berktay's expression, shown in Equation 1, by taking the square root of the base band signal envelope E and then integrating twice to invert the effect of the double partial time derivative. The analogue electronic circuit equivalents of a square root function is simply an op-amp with feedback, and an equalizer is analogous to an integration function. However these topic areas lie outside the scope of this project.
p_2(x,t) = K \cdot P_c^2 \cdot \frac{\partial^2}{\partial t^2} E^2(x,t)
Where
• p_2(x,t) =\, Audible secondary pressure wave
• K = \, misc. physical parameters
• P_c = \, SPL of the ultrasonic carrier wave
• E(x,t) = \, Envelope function (such as DSB-AM)
This equation says that the audible demodulated ultrasonic pressure wave (output signal) is proportional to the twice differentiated, squared version of the envelope function (input signal). Precompensation refers to the trick of anticipating these transforms and applying the inverse transforms on the input, hoping that the output is then closer to the untransformed input.
By the 1990s, it was well known that the Audio Spotlight could work but suffered from heavy distortion. It was also known that the precompensation schemes placed an added demand on the frequency response of the ultrasonic transducers. In effect the transducers needed to keep up with what the digital precompensation demanded of them, namely a broader frequency response. In 1998 the negative effects on THD of an insufficiently broad frequency response of the ultrasonic transducers was quantified[21] with computer simulations by using a precompensation scheme based on Berktay's expression. In 1999 Pompei's article[10] discussed how a new prototype transducer met the increased frequency response demands placed on the ultrasonic transducers by the precompensation scheme, which was once again based on Berktay's expression. In addition impressive reductions in the THD of the output when the precompensation scheme was employed were graphed against the case of using no precompensation.
In summary, the technology that originated with underwater sonar 40 years ago has been made practical for reproduction of audible sound in air by Pompei's paper and device, which, according to his AES paper (1998), demonstrated that distortion had been reduced to levels comparable to traditional loudspeaker systems.

## Modulation scheme

The nonlinear interaction mixes ultrasonic tones in air to produce sum and difference frequencies. A DSB-AM modulation scheme with an appropriately large baseband DC offset, to produce the demodulating tone superimposed on the modulated audio spectra, is one way to generate the signal that encodes the desired baseband audio spectra. This technique suffers from extremely heavy distortion as not only the demodulating tone interferes, but also all other frequencies present interfere with one another. The modulated spectra is convolved with itself, doubling its bandwidth by the length property of the convolution. The baseband distortion in the bandwidth of the original audio spectra is inversely proportional to the magnitude of the DC offset (demodulation tone) superimposed on the signal. A larger tone results in less distortion.
Further distortion is introduced by the second order differentiation property of the demodulation process. The result is a multiplication of the desired signal by the function -?� in frequency. This distortion may be equalized out with the use of preemphasis filtering.
By the time convolution property of the fourier transform, multiplication in the time domain is a convolution in the frequency domain. Convolution between a baseband signal and a unity gain pure carrier frequency shifts the baseband spectra in frequency and halves its magnitude, though no energy is lost. One half-scale copy of the replica resides on each half of the frequency axis. This is consistent with Parseval's theorem.
The modulation depth m is a convenient experimental parameter when assessing the total harmonic distortion in the demodulated signal. It is inversely proportional to the magnitude of the DC offset. THD increases proportionally with m1�.
These distorting effects may be better mitigated by using another modulation scheme that takes advantage of the differential squaring device nature of the nonlinear acoustic effect. Modulation of the second integral of the square root of the desired baseband audio signal, without adding a DC offset, results in convolution in frequency of the modulated square-root spectra, half the bandwidth of the original signal, with itself due to the nonlinear channel effects. This convolution in frequency is a multiplication in time of the signal by itself, or a squaring. This again doubles the bandwidth of the spectra, reproducing the second time integral of the input audio spectra. The double integration corrects for the -?� filtering characteristic associated with the nonlinear acoustic effect. This recovers the scaled original spectra at baseband.
The harmonic distortion process has to do with the high frequency replicas associated with each squaring demodulation, for either modulation scheme. These iteratively demodulate and self-modulate, adding a spectrally smeared out and time exponentiated copy of the original signal to baseband and twice the original center frequency each time, with one iteration corresponding to one traversal of the space between the emitter and target. Only sound with parallel collinear phase velocity vectors interfere to produce this nonlinear effect. Even-numbered iterations will produce their modulation products, baseband and high frequency, as reflected emissions from the target. Odd-numbered iterations will produce their modulation products as reflected emissions off the emitter.
This effect still holds when the emitter and the reflector are not parallel, though due to diffraction effects the baseband products of each iteration will originate from a different location each time, with the originating location corresponding to the path of the reflected high frequency self-modulation products.
These harmonic copies are largely attenuated by the natural losses at those higher frequencies when propagating through air.

## Attenuation of ultrasound in air

The Figure provided in[22] provided an estimation of the attenuation that the ultrasound would suffer as it propagated through air. The figures from this graph correspond to completely linear propagation, and the exact effect of the nonlinear demodulation phenomena on the attenuation of the ultrasonic carrier waves in air was not considered. There is an interesting dependence on humidity. Nevertheless, a 50 kHz wave can be seen to suffer an attenuation level in the order of 1dB per meter at one atmosphere of pressure.

## Safe use of high levels of ultrasound

For the nonlinear effect to occur relatively high intensity ultrasonics are required. The SPLinvolved was typically greater than 100dB of ultrasound at a nominal distance of 1m from the face of the ultrasonic transducer. Exposure to more intense ultrasound over 140dB near the audible range (20?40 kHz) can lead to a syndrome involving manifestations of nausea, headache, tinnitus, pain, dizziness and fatigue,[16] but this is around 100 times the 100dB level cited above, and is generally not a concern. Commercially available Audio Spotlight systems operate in the 60 kHz range.[23]
OSHA specifies a safe ceiling value of ultrasound as 145dB SPL exposure at the frequency range used by commercial systems in air, as long as there is no possibility of contact with the transducer surface or coupling medium (i.e. submerged).[24] This is several times the highest levels used by commercial Audio Spotlight systems, so there is a significant margin for safety. For frequencies of ultrasound from 25 to 50 kHz, a guideline of 110dB has been recommended by Canada, Japan, the USSR, and the International Radiation Protection Agency, and 115dB by Sweden[25] in the late 1970s to early 1980s, but these were primarily based on subjective effects. The more recent OSHA guidelines above are based on ACGIH (American Conference of Governmental Industrial Hygienists) research from 1987.

## Use in politics

There are rumors that this technology has been used to send information to candidates during live debates. The sharp sound gradient can be used to send information to a receiver without disturbing the nearby microphone. This was first reported during the infamous Romney Whisper[26]?which NBC later identified was simply an audience member picked up by an "open mike" in the broadcast mix, and was not audible to the candidates.[27]

## Further resources

USS Patent 6778672 filed on 17 August 2004 describes an HSS system for using ultrasound to:-
• Direct distinct 'in-car entertainment' directly to passengers in different positions.
• Shape the airwaves in the vehicle to deaden unwanted noises.

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2011-02-13 14:07