(word processor parameters LM=8, RM=75, TM=2, BM=2) Taken from KeelyNet BBS (214) 324-3501 Sponsored by Vangard Sciences PO BOX 1031 Mesquite, TX 75150 There are ABSOLUTELY NO RESTRICTIONS on duplicating, publishing or distributing the files on KeelyNet except where noted! February 26, 1993 NOISECNC.ASC -------------------------------------------------------------------- This file is from the Dallas Morning News of Saturday, February 13, 1993 - Business section. -------------------------------------------------------------------- The following file is most intriguing and applies to one of the root studies of Vangard Sciences and KeelyNet. Keely used compound vibrations and we believe at various phasing differentials. This phase adjustment is known in modern terms as interference or phase conjugation and can be either constructive (additive) or destructive. Use of such principles can lead to phenomena beyond simple cancellation of a signal, but we will stay within the context of the article as given. -------------------------------------------------------------------- Technology Report Silence is gold for companies Experiments seek noise reduction by Rebecca Smith San Jose, Calif. - Imagine summer without the earsplitting roar of power lawn mowers, flying without hearing the whining din of jet engines, running the dishwasher without having to shout over the noise. Companies that make noisy products are looking at an ingenious breakthrough technology that enables them to dramatically reduce unwanted sounds. "Active noise reduction" systems represent the broadest assault on noise pollution since invention of the muffler. Products employing the technology will begin showing up in mass consumer products later this year. In what could be a boost for U.S. competitiveness, about 75 patents covering product-specific applications of the technology are controlled by two U.S. companies. "It'll be part of the next wave of luxury home appliances and cars," says technology analyst Dan Hutcheson, president of VLSI Research in San Jose. "Right now, it's expensive, but the cost should come down fairly fast as volumes build." The idea of active noise reduction dates back to a 1936 patent for a "process of silencing sound oscillations" by German inventor Paul Lueg. But commercial execution required invention of the microchip. The concept is simple. Fight fire with fire. Page 1 Here's how it works : Start with an irritating noise, say, that of an air compressor. A microphone samples the noise and sends a signal to a microchip analog-to-digital converter, which translates the sound waves into computer language. It creates a digitized blueprint of the sound, then passes the blueprint to a digital signal processing chip that analyzes the sound's magnitude and frequency. The digital sound processor (DSP) then computes WHAT pattern of sound waves would be EQUAL but OPPOSITE - a MIRROR IMAGE. (180 degree shifted for perfect cancellation...Vangard) That sound profile (signature) is then converted back from a digital to an analog representation. An audible sound wave is created and amplified through speakers or a headset. When the yin-and-yang sound patterns collide - the whole process takes a fraction of a second - they largely cancel each other out. The loud air compressor noise becomes a quiet hum. Advanced systems continuously sample the ambient noise level, correcting and re-correcting. They follow noises as they change, such as engines accelerating. "Most of these systems are still in the experimental stage," says Mike Collins, a manager of digital signal operations at Motorola Corp. in Austin. "In a couple of years, it has the potential to become a commonplace consumer item that will make quieter dishwashers, quieter airplanes and so forth." Most of the patents required to make a DSP-based noise reduction system work are owned by two small U.S. companies : privately held Active Noise and Vibration Technology in Phoenix and publicly held Nose Cancellation Technologies in Stamford, Conn. They are working with Motorola and Analog Devices of Norwood, Mass. to develop the best chips. Other companies are expected to become active players in coming years, at least at the chip-production level. Active Noise says it will have headsets on the market this year carrying a price tag of about $250. They'll be marketed primarily to workers in noisy industrial settings, where they will replace earplugs as safety equipment. Unlike earplugs, which block sounds indiscriminately, the headsets will be programmed to target low-frequency, repetitive sounds that bother most people. A jackhammer operator, at least theoretically, will be able to operate his or her machine and still converse with a co-worker without shouting. As brilliant as noise reduction technology sounds, not everybody is getting on board yet. "The more mainstream approach is to try to reduce noise at the source," says engineer Tom Mitchell, head of the Noise Technology Center at General Motors Corp's Power Train Division in Pontiac, Mich. "Anything you add to a vehicle to susceptible to failure, and there's some added cost associated with a noise reduction system." Mr. Mitchell says GM has devoted considerable resources to reducing unwanted vibrations and noise in automobiles. Fluid-filled engine mounts, developed eight years ago, are an example of a simple device that eliminates noise by reducing the transfer of vibrations from the engine to the frame of the car. Page 2 "I could bore you for hours with all the stuff we've developed," says Mr. Mitchell. "Like double-wall, insulated exhause pipes and sound absorbers in the headliner. We devote a lot of energy to reducing noise, because customers tell us it's one of the best mechanisms they have for assessing quality." Reducing noise can get kind of tricky. Nobody wants road noise, thus tire makers have sound standards to meet. "On the other hand, nobody wants absolute silence. They want some feedback that the engine is there. That's where an electric car can be eerie," Mr. Mitchell says. The key to the noise-cancellation feature of DSP systems rests in the software that's built into the chips. That's where most research and development energies are being expended. The chip has to be told which sounds to attack and which to leave alone. "You don't want to cancel the sound of a great Porsche engine," says Tom Hesse, founder and chief executive officer of Active Noise in Phoenix. In some cases, noise suppression systems actually do more than eliminate an irritation or a safety hazard. They can improve performance. Systems are being developed to replace the entire exhaust system and muffler, thus eliminating the back pressure that the muffler creates. "As a result, you get up to a 5 percent improvement in gas mileage," says John McCoy, president of Noise Cancellation Technologies. Many companies - including Boeing Co., Mercedes Benz and Whirlpool Corp. - confirm they are looking at noise reduction systems but don't want to comment on their research progress because they don't want to tip off their competitors about the timing of the introduction of improved devices. "I know there's a lot of work going on here, but it's highly proprietary," says Boeing spokesman Tom Cole. Meanwhile, designers at Noise Cancellation and Active Noise are busy drumming up interest. So far, most of their income has come from licensing big companies to develope their own systems for specific products. When they come to market, there may be some interesting twists. "We could use it to do more than reduce noise. It could create sounds," says Active Noise's Mr. Hesse. "We probably could make a Honda Civic sound like a Ferrari." Better yet, how about one that can tune out, "Are we there yet?" -------------------------------------------------------------------- If you have comments or other information relating to such topics as this paper covers, please upload to KeelyNet or send to the Vangard Sciences address as listed on the first page. Thank you for your consideration, interest and support. Jerry W. Decker.........Ron Barker...........Chuck Henderson Vangard Sciences/KeelyNet -------------------------------------------------------------------- If we can be of service, you may contact Jerry at (214) 324-8741 or Ron at (214) 242-9346 -------------------------------------------------------------------- Page 3