Melville, New York, November 1, 2000
What are some ways of solving the noise problems on the space station? How does liposuction work at the nanometer scale? How can sound waves "smell" the amount of specific chemicals in a beer brew?
These and other questions will be addressed at the Joint Meeting of the Acoustical Society of America (ASA) and NOISE-CON 2000 to be held December 3-8, 2000 at the Newport Beach Marriott Hotel in Newport Beach, California, about 30 miles south of Los Angeles. Over 850 papers will be presented. The ASA is the largest scientific organization in the United States devoted to acoustics, with over 7000 members worldwide. NOISE-CON is arranged through the Institute of Noise Control Engineering of the USA (INCE-USA).
We encourage you to visit ASA's "ASA Press Room" (http://www.acoustics.org) before and during the meeting. Starting the week of November 12 the site will contain lay-language versions of selected papers to be presented at the meeting.
The Sounds of Liposuction Soundscapes in Mainstream American Films A Kingdom of Sounds Speech Privacy in Office Spaces Artificial Ears and Noses International Noise Control Efforts The Secret of Throat Singing Space Program Acoustics Ultrasonic EyeGlasses for the Blind Theme Park Acoustics Ultrasound Contrast Agents Acoustic Refrigerators: The 2000 Model Year Music in the Age of Confucius and Other Asian Dynasties Acoustical Land Mine Detectors Musical Illusions in Different Populations Acoustics of Toll Booths
UCLA researchers have discovered a link between a popular form of cosmetic surgery and a hot topic in physics research. This link may help researchers to develop new noninvasive forms of surgery using ultrasound. Hospitals around the world are now offering ultrasound-assisted liposuction (UAL), in which a probe shines intense ultrasound to liquefy fat tissue, which is then easier to remove with a vacuum pump. But how does it work? Carlos Camara and his colleagues at UCLA realized that the tip of the UAL probe emits a blue glow which indicates temperatures hotter than those on the sun. The researchers have matched this glow to that produced in a phenomenon known as sonoluminescence (SL), in which sound aimed at a substance (such as liquid water) creates bubbles which implode and release a flash of energy . This conversion of sound into light---representing a trillionfold concentration of energy into a nanometer-scale region---appears responsible for liquefying the fat cells in liposuction. Curiously, the researchers have noted that the SL mechanism appears to preferentially liquefy fat cells over other kinds of cells which surgeons wish to keep intact. (2aBB12)
Whether or not we consciously realize it, we have come to expect a certain acoustical "vocabulary" in mainstream films. Barbara Flueckiger (firstname.lastname@example.org) at the University of Zurich's Institute of Film Theory will present a study of 96 American films produced from 1926 to 1995. Many of these films won Academy Awards for Best Sound. Flueckiger studied the techniques that the films employ to establish fictional, yet natural-seeming "soundscapes." She concludes that the film industry "developed a rather restricted vocabulary" to depict the sounds of specific places. She reasons that "film soundscapes have a clear communicative function in contrary to natural soundscapes, which contain random noises." For 1930s and 1940s movies, she found that filmmakers avoided any sounds that were extraneous to the narrative, but this changed dramatically with the advent of widescreen formats and multi-channel sound systems, with different sounds emanating from different speakers to create panoramic environments. (2aNSa2)
Many animal vocalizations contain important components in the realm of infrasound, acoustical signals that are often too low-pitched for humans to hear, with frequencies of 20 Hertz and below. Elizabeth von Muggenthaler of the Fauna Communications Research Institute (email@example.com) in North Carolina will present a study of infrasound-containing vocalizations in 22 Siberian and Bengal tigers. While the tigers' low-pitched roars may help them to mark territory, their ability to hear low-frequency sounds may also help them detect and locate prey in dense jungles having limited visibility. When played back, the infrasonic roars also elicited distinct behavioral responses in other tigers (3aABb1). Von Muggenthaler will also describe a portable instrument which she has used to analyze, in real-time, the infrasound-containing vocalizations of tigers and numerous other animals including elephants, rhinoceroses, and giraffes (4aAB2).
With our increasingly information-based economy, and the growth in the number of "knowledge workers" who need silence to concentrate, it becomes even more important to develop work spaces free of disruptive noises. Acoustics researchers are working to increase speech privacy in offices. Heakyung C. Yoon of Carnegie Mellon University (firstname.lastname@example.org) studied the effect of noise on the performance of workers in three arrangement plans of open workplaces, and found that an arrangement known as the "triangular configuration in open plan" produced significantly different results than did a rectangular configuration and a combination of open and closed office spaces (5aAA5). Kenneth P. Roy, an acoustical consultant in Pennsylvania, will present results of lab and field measurements of the noise conditions in closed office spaces, and will discuss potential design solutions (5aAA3).
Flavio Noca of the Jet Propulsion Laboratory in California (email@example.com) and his colleagues will describe acoustic sensors which are based on stereocilia, the hairlike inner ear structures that are involved in motion detection. Their devices may ultimately be small and sensitive enough to measure the sounds generated by moving microorganisms and nano-scale biological processes such as those responsible for metabolism. Arrays of these devices could possibly lead to an artificial cochlea, or inner ear. In addition, the devices could function like insect "stridulators," the body parts which rub together to produce sounds useful for their communication. To demonstrate the potential of this design, the researchers have built acoustics sensors based on arrays of carbon nanotubes (2aEA2). Edward J. Staples of Electronic Sensor Technology in California (firstname.lastname@example.org), will present the zNose, a device that can precisely analyze the chemical content of vapors in seconds. Sending a stream of helium gas and the vapor of interest through a specially coated column causes the vapor's constituent chemicals to split up and travel at different velocities. Emerging from the column at different times, each constituent lands on an acoustical detector, which changes its frequency of vibration depending on how much of the particular chemical is present. Sutter Home is using zNose to monitor its wines, and beer companies are employing the device to determine the quality of brews. The sensor can detect pollutants, explosive materials and other volatile and semi-volatile compounds with up to part per trillion sensitivity. (2aEA4).
The World Trade Organization has identified international standardization as a key for worldwide free trade. Klaus Brinkmann of PTB in Germany (email@example.com) will present an overview of efforts for setting international standards in acoustics (0pNSe1). Many other talks at the meeting center on efforts by international organizations to set standards for the control of noise. Inspired by recent guidlines issued by the World Health Organization, acoustical consultant David Lubman (firstname.lastname@example.org) and his colleagues will describe an international initiative to assist developing nations in their efforts to achieve proper acoustics for their classrooms (1aNSc1). Researchers are responding creatively to a European Union goal for reducing road noise in densely packed cities. Tor Kihlman of the Chalmers University of Technology in Sweden proposes the concept of identifying quiet zones in cities and protecting them, similar to the way that government agencies preserve wilderness areas in national parks. Rather than trying to reduce the noise levels at all points of a city, this concept would amount to exploiting its "spatial noise level variations" (2aNSa6).
Most singers can produce only one tone, or note, at a time. But the late physicist Richard Feynman, an avid musician, introduced many people in the Western world to the throat singers of Tuva, a small Central Asian republic near Mongolia. The Tuvan singers can simultaneously produce two distinct tones--an eerie, low-pitched drone and a higher-pitched voice which carries the melody. Presenting magnetic resonance images of a throat singer's vocal tract, Seiji Adachi of the ATR Human Information Processing Research Laboratories in Japan (email@example.com) and a colleague have concluded that a specific portion of the rear vocal tract enables the singers to carry on a melody while enabling the drone. To check their hypothesis, the researchers have successfully produced artificial electronic versions of the two simultaneous tones, by developing a computer model of the vocal tract. (3aMU6)
The International Space Station (ISS) is a work environment like any other. Controlling acoustics is important because the crew will be confined to the station and exposed to the sounds for a long time. The station has suffered from noise problems due to loud fans, reverberating surfaces and glitches in the communications system. But acoustical scientists have been working overtime with space station designers to solve these problems and reduce noise to acceptable levels. Jerry R. Goodman (firstname.lastname@example.org), leader of ISS acoustics for the NASA Johnson Space Center in Houston, will discuss the challenges of developing the proper acoustics for the space station (1pNSc8). Other efforts are underway to develop next- generation technologies for space missions. Michael E. Hoenk (email@example.com) of the Jet Propulsion Laboratory (JPL) will present an atmospheric humidity sensor that takes measurements 10 times faster than conventional designs. Tested in Atlantic hurricanes, the acoustics-based sensor is also being developed as a portable instrument for monitoring humidity in the space station (2aEA3). Yoseph Bar-Cohen of JPL (firstname.lastname@example.org) will describe the emerging technology of ultrasonic motors (USM). These light, compact, low-power devices will play important roles in future space missions. Aiming to develop technologies for the Mars environment, the researchers have created a robotic arm with such motors, which can operate at temperatures below -235 degrees Fahrenheit and pressures that are a fraction of those on Earth (2aEA1).
Bats and dolphins perceive their world with built-in sonar systems that broadcast ultrasound waves to detect objects in their environment. Researchers intensively study these natural sonar systems for reasons beyond learning more about these particular animals. There is the possibility of applying this knowledge to aid people who are vision-impaired. In a special invited lecture, Leslie Kay of Sonicvision in New Zealand will discuss ultrasound devices that can provide auditory information about spatial environments. In the past, Kay has designed the KASPA sensing system, consisting of head-mounted eyeglasses that broadcast ultrasound waves, which then reflect from surrounding objects. The ultrasound reflections produce audible sounds that tell the wearer about obstacles in the environment. Kay is currently taking things a step further, by investigating the possibility of connecting such a device directly to the auditory channels of the brain. In principle, ultrasound information could be sent directly to the auditory centers of the brain and converted into information that help a person "see" the environment. Kay will discuss the very first explorations of this possibility. (2pABa1)
Amusement parks strive to saturate all of our senses--and sound is an important part of the equation. At its best, sound can suspend our disbelief as we experience a sense-defying ride. At its worst, it can create a noise hazard for visitors and residents of surrounding communities. Describing 20 years of experience in designing soundscapes for theme park rides, California-based acoustical consultant Marshall Long (email@example.com) will discuss theme park soundscapes that illustrate creative use of scientific principles (4aAA1). Robert Bronsdon of the Walt Disney Company will discuss how wind and temperature changes can markedly alter the acoustics of an outdoor ride (4aAA5). Acoustical consultant Steven J. Thorburn (SJT@TA-Inc.com) will discuss lessons learned from the indoor theme park at the West Edmonton Mall, where noise levels were so high that complaints were frequent and guest visits were very short. He and his colleagues applied these lessons to the design of a "theme park under glass": the Knott's Camp Snoopy at the Mall of America in Minneapolis (4aAA3).
One of the greatest breakthroughs in medical ultrasound in recent years is the development of "contrast agents," tiny bubbles typically injected into the bloodstream for medical applications. The bubbles reflect high-pitched sound so well that they improve the images in traditional ultrasound. But researchers are exploring exciting new therapeutic applications for the bubbles. For example, Junru Wu of the University of Vermont (firstname.lastname@example.org) will discuss how the contrast agents, when broadcast with ultrasound, dramatically increase the efficiency of gene therapy in test-tube studies (1pBB2). Sessions 1aBB and 1pBB comprise a "topical meeting" in which the latest advances in contrast agents will be described.
Researchers continue to make advances in thermoacoustic refrigerators, devices that chill objects with sound waves and harmless inert gases instead of moving parts and potentially hazardous refrigerants. Thomas J. Hofler and Jay Adeff of the Naval Postgraduate School (email@example.com) are developing a miniature thermoacoustic refrigerator for cooling computer circuits below their failure temperature in hot environments (3aPA6). The researchers and others are developing solar-powered thermoacoustic refrigerators which could cool objects in remote desert environments (3aPA8, 3aPA9). Ray Scott Wakeland of Penn State (firstname.lastname@example.org) will present a thermoacoustics design that leaves out a usual component known as the stack, a honeycomb-like device where heat gets deposited and temperature differences get built up. Although these "no-stack" refrigerators can operate over a potentially limited temperature range, they offer the promise of increased efficiency (3pPA5).
Bo Lawergren of Hunter College (email@example.com) will describe string instruments known as zithers which were discovered in the tomb of Marquis Yi of Zeng, the ruler of a small, previously unknown state in ancient China. Dating from 400 B.C.-200 A.D, some of the instruments went extinct and others led to important Chinese instruments of the last two millennia such as the qui and zheng. Although the tomb was discovered in 1978, Lawergren published the first Western-language book on the ancient instruments just this year (3aMU4). Robert W. Bagley of Princeton (firstname.lastname@example.org) will present findings on an extraordinary set of 65 bells also found in the tomb. With a range of 5 octaves and an unusual scale, it has been a mystery as to how these bells were designed and cast, but Bagley will present a hypothesis on their construction (3pMU2). Yang-Hann Kim of the Korea Advanced Institute of Science and Technology will present studies of ancient Korean bells from the Silla and Korea dynasties. These bells are unique in that they create beats when struck. They also contain pipes acting as a "high-pass filter" which dissipate high-frequency sound very rapidly (3pMU3).
Improvements continue in the use of sound waves to detect buried land mines. Stephane Guyonic of DCE/GESMA in France (email@example.com) will present the first results of a new sonar technique for detecting and classifying mines in shallow and very shallow water. Conducting experiments in a shallow water area with a sea floor made of rough sand, Guyonic reports that "three-dimensional imaging techniques have been used to process the data and very good results have been obtained." (5pPA1). Dimitri Donskoy of the Stevens Institute of Technology in New Jersey will discuss further development of a system for discriminating mines from other objects, such as pipes and containers (5pPA2)
Researchers will present the latest studies on a "musical illusion" known as the tritone paradox, which consists of a sequence of specially generated musical tones. Earlier studies have shown that those with Californian mothers tend to hear the tritone sequence as rising in pitch, while those who had grown up in the South of England typically hear the tones as descending. The paradox suggests that early exposure to speech influences how we perceive music and spoken words later in life. To better understand this phenomenon, researchers are now studying the tritone paradox in other populations. Meredith Haugen of Minnesota State University has found that Midwesterners tend to hear the paradox similar to those from California (3pPP13), while Magdalene H. Chalikia of Minnesota State has found that Swedish listeners tend to perceive the tritones similarly to British listeners (3pPP12). She has also found that Greek bilingual listeners hear the tritone paradox differently than either California or English populations (3pP11). Diana Deutsch of UC-San Diego (firstname.lastname@example.org), who helped to pioneer the original studies, has found that bilingual speakers perceive a musical illusion in accordance with their first language (4aMUb1).
One of the toughest outdoor working environments, from an acoustical point of view, is the highway toll booth. Jeffrey P. Feist of Purdue University (email@example.com) and colleagues are developing solutions to improve the acoustical conditions for these work spaces. Toll booths are partially open enclosures with reflecting walls that may even amplify traffic noise. The traffic noise creates unpleasant working conditions and hampers communication between attendants and drivers. Since low-frequency vehicle noises are believed to play a large role in hampering the communication, the researchers are developing specially designed noise-canceling headsets for eliminating those frequencies. The researchers are also running computer models evaluating structural changes that may improve acoustical conditions in the booths. (5aAA6)
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