Public Release: 

Ultrasound mammography, volcano monitoring for aircraft safety

Hawaii meeting to feature latest results in the science of sound

American Institute of Physics

What happens when sound is aimed at clogged arteries? How can inaudible noise from volcanic eruptions prevent costly delays for airplanes flying near them? How might a new ultrasound method for breast-cancer exams reduce false positives -- and the anxiety that accompanies them? Why may power tools pose a higher risk to hearing than conventional tests may suggest?

These and other questions will be addressed at the Fourth Joint Meeting of the Acoustical Society of America (ASA) and the Acoustical Society of Japan (ASJ), which will take place from November 28-December 2, 2006 at the Sheraton Waikiki and Royal Hawaiian Hotels in Honolulu, Hawaii. Acoustics is the science of sound and its applications. Over 1600 papers will be presented.

We encourage you to visit ASA's "World Wide Press Room" ( before and during the meeting. In the next week, the site will contain lay language versions of almost 20 meeting papers. These papers will enable you to cover the meeting, even if you can't leave your desk.

At a plenary session on December 1, ASA will present its 2006 Science Writing Awards in Acoustics for Journalists to producer Radek Boschetty for "The Noisy Ape," a BBC World Service radio documentary. The Science Writing Award to Professionals in Acoustics goes to "Sound Ideas," an article in Physics World by Taras Gorishnyy, Martin Maldovan, Chaltanya Ullal, and Edwin Thomas. Information on how to enter next year's science writing award can be obtained by contacting Ben Stein.

Reporters covering the meeting can receive a complimentary press badge to attend all sessions. Please fill out the reply form if you are interested in attending the meeting and/or receiving a copy of the book of abstracts. For media inquiries during the meeting, please feel free to contact Ben Stein, who will be available to facilitate your requests, from contacting speakers at the meeting to obtaining background material on meeting topics.

The following items describe some highlights from among the many papers being given at the meeting. Full abstracts of the presentations mentioned below can be viewed at the ASA Meeting Abstracts Database ( by typing in the last name of the author or the appropriate paper code.

The threat of breast cancer moves many women to seek regular mammograms. Unfortunately, the interpretation part of mammography can result in false-positive findings, and an estimated 1 million women per year are subjected to anxiety about cancer. For every 100 biopsies undertaken, 80 come back negative. The psychological costs and the expense (billions of dollars in the U.S. each year) of the original spurious readings have made reducing the false-positive rate a priority among medical researchers. At the Karmanos Cancer Institute in Detroit, Neb Duric ( and his colleagues use ultrasound waves instead of x rays to image breast tissue. According to Duric, the advantages of using ultrasound over x rays are that no radiation is used and compressing the breast is not necessary. In the new approach, unlike conventional ultrasound imaging, detectors completely surround the breast, so both reflected and transmitted waves are recorded. This means that three quantities -- sound reflectivity, speed and attenuation -- and not just reflectivity are measured. About 100 patients have been examined so far with the new method. Duric says that the spatial resolution of his device is a bit lower than with x-ray or with conventional ultrasound (recording only scattered sound waves) imaging, but that the threefold nature of the sound information will lead to a superior differentiation of tumor masses, meaning a much lower false-positive rate. (Paper 1pBB5)

Male humpback whales are known for their courtship songs, and both males and females are believed to use vocalizations while hunting for fish. Now Michael Noad ( of the University of Queensland in Australia and his colleagues have demonstrated that humpback whales possess a vastly more elaborate language than previously known. Noad's team has catalogued at least 622 different sounds the whales use in different contexts, for example between mother and calf or among large groups of adults. (4pABa4)

Sound waves may provide a noninvasive means to restore blood flow in patients with coronary artery disease. Hiroaki Shimokawa of the Graduate School of Medicine of Tohoku University in Japan ( will present a new medical acoustics application, called extracorporeal cardiac shock wave therapy, for treating myocardial ischemia, the lack of blood flow to heart muscle. The condition often results from atherosclerosis, or clogging of the arteries. From outside the body, the researchers aim sound waves that travel to the heart and help to restore blood flow, making the technique completely noninvasive, unlike surgery or even gene therapy. According to the researchers, the technique ameliorates myocardial ischemia and related symptoms in patients with "end-stage" coronary artery disease (in which surgery is no longer viable) without any adverse effects. The researchers are currently performing a double-blind clinical study to further confirm the usefulness and safety of their technique. (2aBB1)

New data suggest the risk of hearing loss from power hand tools -- such as circular saws, sanders, and impact hammers -- could be much higher than previously thought. Current industry standards measure noise levels in unloaded conditions, meaning while the tool is running at full speed but without performing any work. But real-world tests, such as measuring the noise produced when actually sawing wood, show noise emissions are much greater and more hazardous than existing test standards would indicate. Charles Hayden ( of the National Institute for Occupational Safety and Health will present the data and suggest that power tool users request more realistic testing and clearer labeling from manufacturers. (2pNSb1)

A US-Japan team has found new evidence that the rhythm of one's native language influences how that individual hears the rhythms of non-language sounds such as music and the ticking of clocks. When native English speakers listen to the ticking of a clock, they hear "tick-tock," even if the clock's sounds are identical (try this with a wristwatch). This is because people naturally group the individual sounds that they hear into larger rhythmic units. Previously, researchers assumed that speakers of all languages grouped sounds into patterns of short-long (e.g., "tick-tock"). However, the research team discovered, Japanese listeners tend to group sounds into long-short patterns. Possible reasons for the difference, the researchers say, come from the influence of native languages. English has many linguistic chunks that start with a short element and end with a long one, such as "the dog" and "to eat." (English-language poets frequently utilize this property in the most common verse form, iambic pentameter.) In contrast, the Japanese language has many long-short patterns (e.g., Mari-ga, hon-wo), mirroring how Japanese speakers tend to hear the rhythms of grouped sounds. This work suggests that language can influence even very basic aspects of sound perception. The researchers plan to test their hypothesis by predicting how speakers of other languages hear music and other non-linguistic rhythms. (3aPP5; contact John Iversen or Aniruddh D. Patel, The Neurosciences Institute, San Diego,,

Acousticians are working to provide more accurate warning systems for an ever-present aviation danger in volcanic zones. When a jet aircraft flies into the ash from a volcanic eruption, the silicon-based particles from the eruption can enter jet engines and melt, potentially impairing and destroying the engines. In the last 20 years, more than 200 aircraft have interacted with volcanic ash. At least seven cases caused loss of engine power, but fortunately there have not yet been any catastrophes. Yet major limitations exist with current methods of detecting ash at high altitudes. After eruptions, large swaths of airspace are often closed for unnecessarily long periods of time, causing increased costs and delays. Working on efforts to provide more accurate early notifications of volcanic ash injected in the sky, Milton Garces of the University of Hawaii, Manoa ( will describe a prototype system known as ASHE (Acoustical Surveillance for Hazardous Eruptions). In January, an international team of researchers deployed the system in Ecuador, an ideal testing ground since that nation has multiple active volcanoes within a relatively small region. Throughout the year ASHE detected infrasound (sound waves too low-pitched for the human ear to detect) associated with explosions, seismic activity, and flows of debris. ASHE detected distinctly different infrasound signals for potentially dangerous ash-rich eruptions (July and August 2006) and a less risky eruption (May 2006) that injected very little ash in the atmosphere. According to Garces, the results suggest that such infrasonic monitoring can provide valuable eruption information that may improve future early warning systems for aviation safety. (1pPAa2)

In order to study the effects of laughter on health, scientists at the Osaka Electro-Communication University have developed a system for monitoring a person's laughs throughout the day. Masafumi Matsumura ( will describe the "Laughometer," a wireless system worn around the neck that detects the vocal cord vibrations typical of laughter as transmitted through the bones. The system can distinguish up to 90 percent of laughs from vibrations produced by speech. The goal is to provide a tool for better, more accurate studies of laughter's impact on health. (1pSC21)

Consumers were once bombarded by advertisements that proclaimed the effectiveness of noise control features included on dishwashers. Each manufacturer would utilize their own technique for evaluating the noise level of the dishwashers they produced; therefore multiple companies claimed their product was the quietest on the market. Kevin Herreman of Owens Corning ( will describe a new protocol for evaluating the noise generated by dishwashers. Taking into account the power setting for the complete dishwasher cycle, the protocol was created as a result of greater interest among retailers to effectively market quietness as a selling point for appliances. This procedure provides an objective measure of performance that the consumer can use as a guide to find a quieter dishwasher. (5pNSb2)

W. Tecumseh Fitch of the University of St. Andrews in Scotland ( will present new insights on how mammals and other vertebrates make some of their most strange and impressive vocalizations. According to Fitch, numerous fascinating modifications of the basic vocal apparatus-the larynx and vocal tract--can be found in diverse animal species. For example, the male hammerhead bat has a larynx so enlarged that it fills the chest cavity, pushing the lungs and heart down into the abdomen. Lions and other big cats have massive vocal pads within the larynx. Their very loud roars contain sounds far lower-pitched than those a human can produce. Using a combination of acoustic analysis and computer modeling, combined with direct high-speed video observation of the laryngeal vibrations of such animals as Siberian tigers and monkeys, Fitch and his colleagues are gaining knowledge on the acoustic principles underlying such impressive vocalizations. However, he says, certain vocal adaptations remain mysterious, such as the laryngeal air sacs seen in many primates including our own nearest cousins, the great apes. The air sacs can inflate during vocalization, but their acoustical function remains poorly understood. Recent fossil finds show that early human ancestors (Australopithecines) also possessed such air sacs, greatly increasing the interest in understanding the acoustic function of these mysterious structures, Fitch says. (3pAB1)

Anyone who has walked into a crowded party, with music blaring in the background, will remember the first impression of the sound as a single loud noise. In short order, however, different sounds begin to emerge as one listens to a few speakers, hears the melody from the band, or even focuses upon one instrument. According to University of Maryland researcher Shihab Shamma (, this ability arises from auditory nerve cells in the brain re-tuning themselves to specific sounds. What is surprising, according to Shamma and colleagues Mounya Elhilali and Jonathan Fritz, is that the re-tuning of auditory neurons in adult mammal brains happens very rapidly, suggesting that the developed brain is even more "plastic" or adaptable than previously realized. Humans navigating a cocktail party scene might be tuning their neurons to specific voices (and hence tuning out others), or aligning their sensitivity to the acoustic features of one instrument in the band. As scientists build an understanding of the mechanisms that cause this rapid tuning, he says, researchers will be able to mimic these abilities and build more effective hearing aids and cochlear implants, as well as automatic speech recognition systems that can withstand moderate levels of noise and clutter. (3aAB1)

Did the Ancient Mayans possess acoustical knowledge far ahead of their time? A consensus is emerging that the answer is yes, according to acoustical consultant and ASA fellow David Lubman (, who will present a newly detailed study of the ~1100-year-old Great Ball Court (GBC) at Chichen Itza in Mexico. Two remarkable acoustical features of the architecturally unique court were noticed during excavation in the 1920s, but never explained or interpreted. A "whispering gallery" between two temples permits visitors to hear each others' whispers at a distance of about 460 feet apart. A profound set of echoes is heard between the playing field's two massive parallel walls, about 270 feet long, 28 feet high, and 119 feet apart. Until recently, most archaeologists dismissed acoustical features at Mayan sites as unintended artifacts. Stimulated by archaeological acoustic studies and reports since 1999, eminent Mayan archaeologists Stephen Houston and Karl Taube have reinterpreted certain Mayan glyphs as vibrant sounds and ballcourt echoes, and have called for a new archaeology of the senses, especially hearing, sight, and smell. By interpreting architectural, psychoacoustic, and cognitive features of the GBC in the context of ancient Mayan culture, Lubman speculates that acoustical effects at the GBC may be original design features. (4pNSb4)


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