Ultrasound Mammography, Latest Results In The Science Of Sound

Main Category: Conferences
Also Included In: Medical Devices / Diagnostics;  Ear, Nose and Throat
Article Date: 22 Nov 2006 - 7:00 PDT

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What happens when sound is aimed at clogged arteries? 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.

PROGRAM HIGHLIGHTS

The following items describe some highlights from among the many papers being given at the meeting.

ULTRASOUND MAMMOGRAPHY 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)

CLEARING CLOGGED ARTERIES WITH SOUND

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)

NOISE HAZARDS FROM POWER TOOLS COULD BE UNDERESTIMATED

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)

WHY "TICK-TOCK" TO ENGLISH SPEAKERS SOUNDS LIKE "TOCK-TICK" TO JAPANESE SPEAKERS

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.)

LAUGHOMETER: IS LAUGHTER GOOD FOR YOU?

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)

PROTOCOL FOR QUIETER APPLIANCES

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)

UNRAVELING THE MYSTERIES OF ANIMAL VOCALIZATIONS

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)

CHANGING YOUR MIND AT A COCKTAIL PARTY

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)

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Contact: Ben Stein
American Institute of Physics

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