Exploring the world only for its sounds may at first seem to be a limited endeavor, but instead it provides insight into an endless number of interesting questions. How is the squeal of a train wheel intimately connected to the heavenly tones of a violin? Could sound waves replace hypodermic needles and scalpels in the hospital of the future? Do babies begin to learn their native language even before birth?
These and many other questions will be addressed at what will be the biggest conference ever devoted exclusively to the science of acoustics: the Joint 16th International Congress on Acoustics (ICA) and the 135th Meeting of the Acoustical Society of America (ASA), to be held June 20-26, 1998 at the Seattle Sheraton Hotel and Towers and the Westin Seattle Hotel in Seattle, Washington.
At the meeting over 1500 papers will be delivered from acoustical scientists and engineers from 49 countries, including Japan, Italy, France, England, Estonia, Brazil and many others. The ICA is held every three years under the authority of the International Commission on Acoustics, an affiliated member of the International Union of Pure and Applied Physics (IUPAP). The ASA is the largest scientific organization in the United States devoted to acoustics, with nearly 7000 members.
For the first time at an ASA meeting, we will operate a newsroom and offer a series of news conferences. A list of news conferences and newsroom phone numbers will be available in early June. Reporters interested in attending the meeting should pre-register by returning the form at the end of this release, or register on-site by supplying the appropriate credentials.
Before and during the meeting, we encourage you to visit ASA's "World Wide Press Room" (http://www.acoustics.org). Right now at this website, you can access a searchable database of meeting abstracts, including all those mentioned in this release. Starting the first week of June, the site will contain numerous lay-language versions of meeting papers.
The following list represents some of the highlights from among the many papers being given at the meeting:
Bloodless Surgery with Sound
Researchers have made exciting progress toward demonstrating how sound waves may someday replace scalpels and stitches in many forms of surgery. Roy Martin of the University of Washington (rmartin@u.washington.edu) and his colleagues have performed experiments with high-intensity ultrasound which show they can significantly reduce the oozing and bleeding that traditionally hinders liver surgery (Paper 2aBV3). Narenda Sanghvi of Focus Surgery, Inc. in Indianapolis and co-workers have developed a technique for using ultrasound to remove diseased prostate tissue (2pBV6). Jean Chapelon of the National Institute of Health and Medical Research in France (chapelon@lyon151.inserm.fr) will describe human clinical trials of ultrasound treatments for prostate cancer (2pBV7).
Injecting Drugs with Sound Waves
Joseph Kost of Ben-Gurion University in Israel (kost@mit.edu) will discuss sonophoresis, the use of sound waves in place of needles to inject drugs such as insulin and interferon directly through the skin (3aBV3). Using this technique, the Ekos Corporation in Bothell, Washington (contact Joe Eichinger, 425-482-1108), is developing an acoustically based insulin-delivery system for people with diabetes. In another area, Leonard Bond of the University of Denver (lbond@du.edu) will discuss evidence that ultrasound can enhance the delivery of certain pharmaceuticals through the blood-brain barrier (3aBV4). Michael Tanter of the University of Paris (michael@clara.loa.epsci.fr) will discuss experimental efforts towards noninvasive brain imaging with ultrasound (1pBV4).
The Synergy Between Ultrasound and Cancer Therapy
Yet another exciting discovery in medical ultrasound has recently been made: administering ultrasound during the application of chemotherapy or gene therapy seems to increase the effectiveness of these treatments. In the realm of cancer treatment, George H. Harrison (harriso@umabnet.ab.umd.edu) of the University of Maryland (3pBV1) and Katsuro Tachibana (mm038261@cc.fukuoka-u.ac.jp) of the Fukuoka University School of Medicine in Japan (3pBV4) will describe drugs that can be activated at specific cancer sites using ultrasound. Developing anti-cancer drugs that are activated by ultrasound only at the desired regions can potentially minimize the devastating effects of chemotherapy. In the area of gene therapy, M. Delius of the University of Munich (3aBV2) and Evan Unger (eunger@vms.ccit.arizona.edu) of the University of Arizona (3pBV3) will describe how ultrasound aids the introduction of genetic material in living cells.
The Comprehensive Nuclear-Test-Ban Treaty
India's recent display of its nuclear weapons capability has heightened the importance of the Comprehensive Nuclear-Test-Ban Treaty, the global moratorium on nuclear testing signed by 149 nations (excluding India and Pakistan) that went into effect in the autumn of 1996. To provide a method for verifying this treaty, scientists and engineers are building the first-ever fully global hydroacoustic monitoring system, which will listen to the world's oceans 24 hours a day for evidence of nuclear detonations. At the ICA/ASA meeting, Martin W. Lawrence (mlawrence@ctbto.un.or.at) of the Comprehensive Nuclear-Test-Ban Treaty Organization in Vienna and others will report the latest progress on this network. (Session 4pUW3, 4pUW4)
Jimi Hendrix and the Deliberate Use of Distortion in Music
One of the most influential figures in the world of rock music, Jimi Hendrix was among the first instrumentalists to use distortion as an expressive tool in music. Another pioneer was Eric Dolphy, a jazz musician who in the early 1960s introduced distortion effects in acoustical instruments such as the alto saxophone, bass clarinet and flute. And vocalists instinctively employ distortion as a valuable tool. The acoustical properties of distortion are intriguing, arising from "nonlinear" effects in which changing an input to a signal produces a nonproportional, sometimes greatly magnified, change in the output signal. At session 1pMU, researchers will explain how Hendrix, Dolphy, and others used distortion to create expressive, harmonically rich sonic environments. A demonstration performance, featuring musicians expert in the styles of Hendrix, Dolphy, and others, will be held on Monday afternoon, June 22, immediately following this session.
Those Creatures Have Rhythm
Scientists are attempting to decode the fascinating acoustical rhythms of living creatures to learn new details about their behavior and physiology. Whales generate long rhythmic patterns of sound, and some sounds can travel hundreds of miles underwater. Analyzing "the remarkable cadence" of these patterns, Christopher Clark of Cornell University (cwc2@cornell.edu) will show that whales can retain a rhythm even after minutes of silence (4aAB4). Timothy Forrest of the University of North Carolina (tforrest@unca.edu) will explain how listening to the daily, annual, and shorter-term rhythms in the acoustic signals of insects could help scientists monitor changes in insect populations (4aAB2). Studying how female midshipman fish distinguish between the concurrent mating calls ("hums") of males singing to them together, Andrew Bass's lab at Cornell University (ahb3@cornell.edu) will present evidence that the regularly repeating acoustical "beats" produced by the concurrent hums get converted into rhythmically timed nerve signals in the brain, allowing individuals to distinguish between the different songs (4aAB1).
Reducing Noise in the Transportation Landscape
In an unexpected discovery, researchers have found that highway noise barriers with jagged edges are better at shielding sound than those with smooth walls. Penelope Menounou and her colleagues at the University of Texas (menounou@mail.utexas.edu) have come up with an explanation for this phenomenon (1aNSb2). Maria Heckl of Keele University in England (m.a.heckl@maths.keele.ac.uk) will describe how the "curve squeal" created by trains as they round a bend is closely related to the exact friction-based process responsible for creating sound in a bowed string instrument such as a violin. To actively control these noises, Heckl has devised a feedback system that stabilizes the vibrations of the train wheels (2pSA1). Investigating the noise from another increasingly popular mode of transportation--motorcycle scooters--Cho H. Lu of the Industrial Technology Research Institute in Hsinchu, Taiwan (830562@mirl.itri.org.tw) will show how padding the exhaust pipe and separating the power transmission box from the rest of the scooter can make them significantly quieter (5aNSb2).
Other Important Uses of Sound in Animals
Using a biological form of sonar, fish-eating flying bats have the amazing ability to detect underwater fish, even though only a thousandth of the energy in their sonar signal penetrates into water, and only a millionth of the original energy gets reflected back. Presenting a theoretical model of this process, Anatoli Stulov of the Institute of Cybernetics in Estonia (stulov@ioc.ee) argues that the bat can nonetheless detect fish easily, by broadcasting sonar of several different frequencies and comparing the results (2pAB7). In separate research, Peter Narins of UCLA (pnarins@ucla.edu) will describe new evidence that a frog employs the electrical "noise" naturally present in its nervous system to aid the transmission of nerve signals in its body (4aAB3).
Wired by Words
One of the most intriguing recent theories in psycholinguistics asserts that babies essentially form all the nerve-cell connections in the brain required to comprehend the sounds of their native language by the time they are a year old, even if they cannot yet vocalize their words. Specifically, Patricia Kuhl of the University of Washington (pkkuhl@u.washington.edu) has proposed the "native language magnet effect," in which the baby's nerve cells wire themselves to perceive distinctions between different types of sounds in its native language. In an effort to understand further how the infant brain wires itself to incoming language information, Kuhl will present new experimental studies of brain activity in 7-month-olds listening to sounds from their native language (3aSC2).
Sonar Monitoring of Seafood
As worldwide consumption of seafood steadily grows and habitats are destroyed, fish populations are becoming badly depleted. While sonar systems have traditionally been employed to find and catch fish, scientists are now improving the technique with specialized networks to study and count the populations of fish and plankton for regulatory purposes. Five sessions (3pAO, 4aAO, 4pAO, 5aAO and 5pAO) will be devoted to this topic. Joseph Luczkovich and colleagues at East Carolina University (luczkovichj@mail.ecu.edu) will describe how sound is used to map fish spawning activities off the coast of North Carolina (4pAO6). Such studies should help governments to develop more sophisticated fish management plans than previously possible.
The Acoustics of Opera Houses
Designing an opera house with good acoustics requires a much different approach than designing a suitable concert hall. For one thing, the size of an opera house should be small, so that a singer's voice can be projected to maximum effect. Secondly, the sound coming from the orchestra must be handled differently from that of a singer, since the instrumentalists are relegated to the pit in opera performance. At session 2pAAa, Maria Ida Biggi of the University of Bonvicini in Italy and others will discuss plans to reconstruct the famous La Fenice opera house in Venice after it was destroyed in a fire. Carmine Ianniello of the University of Naples (maffei@unina.it) will present modern acoustical measurements on the 250-year-old Teatro di San Carlo, believed to be the oldest existing European opera house (1pAAb1). Christopher Jaffe (dcoppola@jhsacoustics.com), an acoustical consultant who helped redesign the Kennedy Center Concert Hall in Washington DC, will discuss nontraditional venues for opera performances and new approaches to stage design (1pAAa2). Leo Beranek (617-576-3141), a world authority on concert and opera hall acoustics, will describe the design of the opera house in Japan's New National Theater, part of a "theater city" that opened in Toyko this past fall (4aAA4).
Latest Advances in Sonochemistry
To trigger chemical reactions in a liquid, forget about changing the temperature, or increasing the pressure--you can use sound waves instead. Aiming ultrasonic waves at a liquid-filled tank creates bubbles that implode and generate highly reactive ions known as free radicals. The free radicals can then attach themselves to chemicals in the tank, and initiate chemical reactions. Scientists envision that sonochemistry can become an environmentally friendly approach to cleaning up waste by using sound to break down large molecules like PCBs into smaller, harmless inorganic molecules. Sonochemistry has potential biomedical uses too. Kenneth Suslick of the University of Illinois (ksuslick@uiuc.edu) will describe sonochemical reactions that create tiny protein-containing spheres. Less than 5 millionths of a meter in diameter, these spheres can travel through the bloodstream readily and can potentially be used as drug delivery vehicles, blood substitutes, and medical-imaging agents (3aPAa2).
What Cats Hear When You Talk to Them
A famous "Far Side" cartoon shows a dog owner giving a long lecture to his pet, who only comprehends his name and registers everything else as "blah blah blah." In real life, scientists are studying how animals convert the sounds associated with communication into electrical impulses that travel to their brains, in order to gain a better understanding of how animals encode communicative signals in their auditory systems. In paper 4aPP1, Bradford May of Johns Hopkins University ( bmay@welchlink.welch.jhu.edu) will discuss a study of how cats convert vowel sounds into patterns of nerve-cell firings for varying levels of sound intensity and levels of background noise.
Plenary Lectures
Internationally recognized experts in acoustics will deliver a series of 16 plenary lectures at the meeting dealing with the hottest topics in acoustics. Some examples include: "How Listeners Find the Right Words," by Anne Cutler (anne.cutler@mpi.nl) of the Max Planck Institute for Psycholinguistics in the Netherlands (June 24); and "Non-Invasive Ultrasound Surgery," by Gail ter Haar (gail@icr.ac.uk) of the Royal Marsden Hospital in England (June 23). In addition, Sadaoki Furui of the Tokyo Institute of Technology (furui@cs.titech.ac.jp) will forecast future directions in speech recognition and speech synthesis technology, including how conversations might be held between machines and humans in the future (June 22); Neville Fletcher of the Australian National Institute (neville.fletcher@anu.edu.a) will explain how one can tinker with the rich mathematical properties of musical instruments such as clarinets to produce innovative sounds (June 26); and Eric Young of Johns Hopkins University (eyoung@bme.jhu.edu) will review the latest insights into how the inner ear converts the sounds that we hear into the electrical code that travels to our brain (June 23).
How Drumsticks and Guitar Shapes Affect Timbre
A middle "C" played on the piano sounds different from the same note played on the guitar because of differences in a quality called "timbre." Both the guitar and piano notes produce pitches with a "fundamental frequency" corresponding to the note C, but each instrument produces varying levels of other, higher frequencies called "overtones" which account for some of the differences in their sound. Sessions 4aMU and 4pMU concern themselves with the effects of timbre in musical sound. James Irwin of Bradley University (jhirwin@bradley.edu) will present a study of how a drumstick's shape and size affects the timbre of the drums that are being played (4pMU2). Constructing guitars of three different shapes--box, triangle, and octagon, researchers at Loyola College in Baltimore (Suzanne Keilson, keilson@loyola.edu) surprisingly found that listeners rated the sounds of the octagon-shaped guitar as highly as those from the traditional box-shaped one (4pMU5). Judith Brown of Wellesley College in Massachusetts (brown@media.mit.edu) has designed an artificial intelligence program that can distinguish between four different types of wind instruments (4aMU6).
Listening for Global Warming
In efforts to monitor climate change in the sea, the Acoustic Thermometry of Ocean Climate (ATOC) experiment broadcasts low-frequency sound waves over long distances in the Pacific Ocean to measure water temperature and other quantities. Exploiting the fact that sound travels through warm water faster than in cold water, the researchers measure sounds' travel times to calculate the water temperature at various parts of the North Pacific. Reviewing more than 15 months of data from the ATOC program, Robert Spindel of the University of Washington (spindel@apl.washington.edu) and other members of the ATOC group will show that the data allow researchers to detect ocean temperature changes with a precision of a thousandth of a degree Celsius per day (1aAO1). These encouraging findings suggest that ATOC--and acoustic thermometry in general--holds promise for providing useful information to the global warming controversy.
Speeding Up Building Construction with Sound
Currently, the building construction process is slowed down by the fact that it takes an unpredictable amount of time for cement and concrete materials to fully dry. Bernhard Tittmann of Penn State University (brt4@psu.edu) will discuss a new acoustical technique for penetrating the surface of these materials to measure when the materials are adequately hardened (2pPAa9). In addition, the researchers are using their technique to investigate the physical and chemical changes that take place in cement during hardening.
New Ways of Studying Auditory Development
Edward Rubel of the University of Washington (rubel@u.washington.edu) will describe how the tools of modern biology can provide molecular-level information on how one's early-life environment can affect the development of hearing (2pPP7). Beverly Wright of Northwestern University (b-wright@nwu.edu) will discuss a promising new technique for training children who have psychophysiological difficulties in perceiving and producing spoken language. According to Wright, approximately 5% of all children who are otherwise unimpaired may have such psychoacoustical deficits (2pPP6). The inner ear not only receives sound; it also makes its own sound, known as "otoacoustic emissions." Now, researchers are using otoacoustic emissions to noninvasively probe the inner ear's function and its development. Discussing the effects of hormones on the development of the inner ear and hearing, Dennis McFadden of the University of Texas (mcfadden@psy.utexas.edu) will discuss his striking recent conclusion that homosexual and bisexual women produce otoacoustic emissions that are more like the male pattern than those of heterosexual women (2pPP4).
Cracking the Mystery of Sonoluminescence
One of the great continuing mysteries in physics is the process of sonoluminescence (SL), in which focussed sound waves in water or other liquids generate bubbles which collapse and generate pulses of light lasting just trillionths of a second and representing a trillion-fold focusing of the original sound energy. Most of the world's experts on this subject will gather together at the ICA/ASA meeting, and new breakthroughs toward understanding SL are expected to be revealed. Having devised a powerful "single-photon-counting" technique for measuring the duration of sonoluminescence pulses, Bruno Gompf of the University of Stuttgart (gompf@il.physik.uni-stuttgart.de) and his colleagues will review their discovery that the red and ultraviolet components of an SL pulse last for the same amount of time, ruling out some prior explanations for the SL phenomenon (5aPAa2). Seth Putterman of UCLA (310-825-2269) will describe two remaining experimental quests in SL: determining the size of the sonoluminescing bubble and the temperature of the region responsible for emitting the light (5pPAa1). Ascertaining and optimizing these quantities may enable scientists to create a "star in a jar"--a tabletop SL apparatus that might be capable of producing modest amounts of nuclear fusion.
Non-Auditory Effects of Noise on Health
Noise can do more than damage hearing. Indeed, it can cause other physiological problems, including many stress-related ones such as raising heart rates and blood pressure. Medical scientists fear that excessive noise in hospitals can compromise the normal development of newborns, especially those in intensive care units. Studying the neonatal intensive care units of an Ottawa hospital, Chantal Laroche of the University of Ottawa (claroche@uottawa.ca) and her colleagues have found that the sound levels largely exceeded those recommended by the World Health Organization to avoid negative effects on sleep. Laroche will address strategies for controlling noise in such units(1aNSa1). Accompanying this session will be a panel discussion on this emerging area of inquiry in acoustics.