June 11, 2008 -- The largest ever meeting devoted to the science of acoustics will take place Monday June 30 through Friday July 4, 2008 at the Palais des Congrès in Paris, France. This news release highlights just a few of the 3,500 talks and posters at Acoustics '08.
More details for journalists covering the meeting are contained at the bottom of this release.
HIGHLIGHTS OF ACOUSTICS '08
1) CLINICAL ASSESSMENT OF BLOOD VESSEL ULTRASOUND
Understanding the mechanics of cardiovascular disease is changing. The old idea of static, clogged "pipes" is now yielding to a more sophisticated concept of cardiovascular disease as an inflammatory process that begins in children as young as 10 years old. The life-threatening end product of this process is an unstable blood vessel lesion -- known as a vulnerable plaque -- that has developed a specific chemical composition and distinct form (thin, fibrous cap) that render it likely to rupture and lead to heart attack.
Detecting vulnerable plaques would be an immense aid for managing heart disease, the leading cause of death and disability in western nations, but traditional imaging methods don't currently detect vulnerable plaque. Antonius FW van der Steen, (firstname.lastname@example.org) and his colleagues at the Erasmus Medical Center in Rotterdam, Netherlands, are working to change this with an emerging technology called intravascular ultrasound palpography.
Once threaded through a catheter to reach the target blood vessel, intravascular ultrasound palpography measures the local strain in vessels caused by vulnerable plaque. These measurements help assess the vulnerable plaque's stability and its likelihood of rupture. Clinical trials now underway are testing the validity of using intravascular ultrasound palpography readings as "biomarkers" to help clinicians evaluate the efficacy of various drugs to treat vulnerable plaque. (Talk 1pBBb2, "Quantitative intravascular ultrasound elasticity imaging as an imaging biomarker in clinical trials," will be at 1:20 p.m. on Monday, June 30 in Room 362/363).
2) WHAT HAVE THEY DONE WITH THE STRADIVARIUS VIOLINS?
Almost every baroque violin, including those of Stradivari family, was extensively modified during the conversion to the romantic or modern configuration. What were the acoustic and playing changes? To answer this question, independently of the confounding factors of wood and manufacture, John McLennan of the University of New South Wales (email@example.com) performed an experiment. He built a baroque violin and subjected it to acoustic and playing tests, before and after replacing the neck and fingerboard with longer, heavier, more inclined parts and replacing the gut strings with modern nylon-core strings.
Other changes were also made, including bridge style and position, bass bar, soundpost sizes, and bow used. Loudness was not greatly changed, except for the E string with a long string length. A result of the bridge below the f-holes, some acoustic features survived the changes, and professional baroque and modern style players reported that the instrument preserved some of its personality. Comparisons were made with modern gut strings used by professional baroque players. Besides the acoustic differences, players assessed qualities such as bright/dull, full/thin, open/closed, ease of response, evenness, and dynamic range of the instruments. Averaged over all ratings, the players ranked the romantic set up slightly better than the baroque. (Talk 3pMUa3, "What have they done to the Strads?" will be at 2:20 p.m. on Wednesday, July 2 in Room AMPHI MAILLOT).
3) USING ULTRASOUND AND SHEAR WAVES TO ASSESS LIVER STIFFNESS AND DISEASE
Human livers are under siege because of a global rise in end-stage liver disease related to obesity, alcoholism, and infectious diseases like hepatitis B, hepatitis C, and HIV. Because the prognosis for people with chronic liver disease is related to the progressive growth of fibrotic liver tissue, the search is on for better alternatives to surgical biopsy for detecting fibrosis. Ultrasound-based transient elastography is one alternative. It quickly and non-invasively provides clinicians with a quantitative measure of liver stiffness, a diagnostic trait that correlates well with the degree of destructive fibrotic growth. Knowledge of liver stiffness enables physicians to detect and treat chronic liver diseases, when they are most treatable.
There's just one hitch: Current use of transient elastography is limited to average-weight adults. Obese adults and children are difficult or impossible to assess with transient elastography. Their body size inhibits the passage of the low-frequency shear waves through the liver. This impedance undermines the usefulness of transient elastography because stiffness score is based on the velocity of a shear wave as it passes through the liver.
Now this may change, thanks to work by Laurent Sandrin (Laurent.firstname.lastname@example.org) and colleagues at Echosens, R&D department in Paris, France. They have developed new probes for children and obese patients, and modified stiffness measurement procedures to extend the applications of transient elastography. (Talk 1pBBb8, "Transient elastography: changing clinical practice in hepatology," will be at 3:20 p.m. on Monday, June 30 in Room 362/363).
4) PEOPLE WHO CAN'T CARRY A TUNE EITHER DON'T KNOW OR DON'T CARE
Acoustical analyses of people belting out "Jingle Bells," "Brother John" and a Polish birthday song, "Sto Lat" reveal that most people sing in tune and in time, even without musical training. Moreover, two distinct "phenotypes", or recognizable forms, of impaired singing exist that are linked to perceptual abilities. Establishing this linkage is helpful for designing a music education curriculum.
Dr. Simone Dalla Bella (email@example.com) and colleagues from the University of Finance and Management in Warsaw, Poland, set out to evaluate the proficiency of singing in the general public because little data existed, yet most people believed the majority of people can't carry a tune.
The team individually recorded 42 visitors to a Montreal park whom they asked to sing the familiar anthem of the Quebec sovereignty movement, "Gens du Pays." They compared them to professional singers' renditions. When the non-musicians were instructed to sing more slowly, 40 of 42 sang as accurately as the pros in terms of pitch and timing. Next, investigators invited 40 volunteers into their acoustics laboratory in Poland and instructed them to sing "Jingle Bells," and other songs. The investigators then administered a test called the Montreal Battery of the Evaluation of Amusia. From this they identified two phenotypes of impaired singing: off-pitch singers with perceptional deficits who don't know they're landing on the wrong notes, and poor-pitch singers who can tell they're off and sing anyway. (Talk 3aMUa6, "Singing out of tune: Disturbances of vocal performance in the general population" will be at 9:40 a.m. on Wednesday, July 2 in Room AMPHI MAILLOT).
5) PALEOLITHIC ART AND MUSIC RESONATE
Thousands of years later, we can view stone-age art on cave walls, but we can't listen to the stone-age music that would have accompanied many of the pictures. In many sites, flutes made of bone are to be found nearby. Iegor Reznikoff (firstname.lastname@example.org) of the University of Paris reports that the most acoustically resonant place in a cave -- where sounds linger or reverberate the most -- was also often the place where the pictures were densest. And when the most-resonant spot was located in a very narrow passageway too difficult for painting, red marks are often found, as if the resonance maximum had to be signified in some way. This correlation of paintings and music, Reznikoff says, provides "the best evidence for the ritualistic meanings of the paintings and of the use of the adorned caves."
Proceeding into the direction of the best resonance (or echo) that answers to vocal sounds, one is naturally lead to panels with pictures. At the very least, in the dark caves, where hand-held light sources fall off in effectiveness, singing (and listening for resonant reactions) proved to be the best sonar-like way of exploring the caves. A significant returning sound gave some hint of a usable hall ahead in the dark.
On the 5th and 6th of July, Reznikoff will conduct a tour of a prehistoric cave where he will show some examples of the sound-picture relationship. He will also lead a visit to the Basilica of Vezelay where he will illustrate the magnificent resonance. (Talk 4pAAa1, " Sound resonance in prehistoric times: A study of Paleolithic painted caves and rocks" will be at 1:20 p.m. on Thursday, July 3 in Room 242B).)
6) ACOUSTICS, PRIVACY, AND THE WORLD TODAY
Since the end of World War II, privacy has been widely recognized as a fundamental human right. Governments worldwide have signed declarations enshrining it, and generations of politicians have passed laws protecting it. Speech privacy is a natural part of this, and many of the world's privacy laws explicitly secure the right to privacy of speech. The last decade, however, has witnessed sweeping changes that have challenged countries across the globe to balance the need for privacy with such concerns as security, health, and welfare.
Almost by accident, the Internet caused the first wave of change. The incredible increase in information accessibility via the Web drove many nations to develop new privacy laws, including legislation that covers speech privacy. A second wave of change erupted in 2000, when the tech bubble burst. As fallout of this market tumble, governments enacted new laws to improve financial accountability. In response, private companies and organizations had to find new ways to shield their leaders by examining the privacy standards in their own policies. Then came the terrorist acts of 2001. Suddenly an individual's privacy had to be balanced with global security concerns. The fourth wave of change, now upon us, is becoming a growing roar. As more and more baby boomers are turning 60, the healthcare industry has begun racing to build capacity to meet growing needs and now has to address the health effects of noise. The fifth wave, which is coming, is related to the green movement and renewed interest in controlling environmental noise as a pollutant.
All these changes have stimulated new interest in acoustics, says David M. Sykes (email@example.com), a member of an international working group on healthcare acoustics and speech privacy. At the Paris conference, he will review how these five waves of change have affected countries in Europe, North America, and Japan. (Talk 2aAAd1, "Waves of change: Global policies and their impacts on the acoustics profession" will be at 9:20 a.m. on Tuesday, July 1 in Room 253).
7) THE OCEAN CALLS -- SLLAC NAECO EHT
Radio and other light waves cannot penetrate the ocean very far, so how to communicate with underwater vessels? Acoustics is one possibility. Sound waves travel thousands of kilometers through water, but uneven seafloors, currents, and sub-surface waves will completely garble an acoustic message.
Research over the last the last decades has shown that acoustic communication in the ocean is feasible and research in the last ten years has shown that these difficulties can be overcome by playing distorted signals backwards. This so-called time reversal technique is used in astronomy to remove atmospheric blurring and in medical imaging to focus ultrasonic beams.
In several joint experiments with the NATO Undersea Research Centre along the Mediterranean coast, William Kuperman (firstname.lastname@example.org).of the Scripps Institution of Oceanography and his colleagues have demonstrated a time reversal mirror made of an underwater array of receivers and transmitters. When the mirror receives acoustic pulses from a source kilometers away, the signals are stretched out in time due to the different possible paths between the source and the receivers. If these spread-out signals are reversed (emitting the late arrivals first), the ocean will undo its own distortions so that the original sharp pulse can be detected at the source position.
Because the ocean is typically stable enough to allow this time reversal process, the array can send a series of reversed signals that will automatically focus back on the source. This ocean-mediated data stream could allow communication with fixed undersea platforms in the ocean, a submarine or an unmanned submersible vehicle. Similar types of arrays might also improve SONAR by better filtering out unwanted echoes from surrounding objects. (Talk 2aSPa2, "Ocean acoustic time reversal" will be at 8:20 a.m. on Tuesday, July 1, 2008 in Room 343).
8) ACOUSTIC TECHNIQUES FOR MONITORING BIRD MIGRATION
Most bird migration occurs under the cover of darkness, and presently there are almost no reliable or robust techniques for identifying which species are passing as they migrate. By recording the unique flight calls of birds as they fly by night, researchers can develop migration maps for each species that depict the routes and timing of migration. Knowing about these migration patterns is crucial for bird conservation because any plans to conserve birds' stopover habitats require detailed knowledge of the timing and location of their passage.
Andrew Farnsworth (email@example.com) of Cornell University's Laboratory of Ornithology has been using acoustical techniques to study bird migration patterns since 1991. For the past three years, a grant from the U.S. Department of Defense Legacy Resource Management Program has enabled his team to make great strides in the field.
Farnsworth will discuss the methods and scope of his work, which include deploying a recording device to record entire nights of migration for periods of up to 70 days and specially designed software for automatically extracting the sounds of interest from these recordings in order to map the patterns of bird calls as a function of time and location. His presentation will show that acoustic data results from vocal nocturnal migrants correspond with the more traditional methods of bird banding and ground observations and can be an effective and complimentary method of monitoring bird migration. However, his results will also show that there are certain groups of more elusive and rare species that are much better represented in the acoustic data.
The presentation will also feature audio playback of bird records that highlight the ephemeral and unique qualities of these calls. (Talk 2aAB2, "The value of acoustic technologies for monitoring bird migration" will be at 8:20 a.m. on Tuesday, July 1, 2008 in Room 342B).
9) CONSERVATION AND THE TIGER'S ROAR
In Paris, Edward Walsh (firstname.lastname@example.org) from Boys Town National Research Hospital, Douglas L. Armstrong (email@example.com) from the Henry Doorly Zoo, and their colleagues will present the most recent findings of the Omaha Tiger Project, one of the first and most detailed analyses of the auditory properties of tiger calls and tiger hearing. The research has confirmed the previously determined notion that the dominant frequency in at least some tiger calls is in the low frequency range of 200 Hz to 300 Hz. A question of interest to biologists is whether tigers produce calls in the infrasonic ranges, frequencies below 20 Hz that humans are not capable of hearing. The research has shown that although tigers are in fact capable of making these types of calls, and that they may be used when tigers are communicating over long distances, infrasonic energy is not a common feature of most calls studied thus far.
The greater goal of the Omaha Tiger Project is to contribute to ongoing efforts to conserve free ranging tigers, all of which are seriously endangered. Because effective conservation strategies require an accurate knowledge of the number of individuals living in a given territory, and because existing census numbers for tigers are notably inaccurate, the group plans to develop methods to identify individual animals in the wild on the basis of the acoustic properties of their calls. The presentation will feature audio recordings of tiger calls. (Talk 4aABa7, "Acoustic communication in Panthera tigris: A study of tiger vocalization and auditory receptivity revisited" will be at 10:00 a.m. on Thursday, July 3 in Room 342B).
10) EARTHQUAKES UPON EARTHQUAKES
Joan Gomberg (firstname.lastname@example.org), Paul Johnson (email@example.com) and their colleagues from the U.S. Geological Survey and Los Alamos National Laboratory are looking at a newly-recognized seismological phenomenon called dynamic triggering that occurs when faults in the Earth's crust are subjected to transient strains and stresses. These stresses and strains may be caused by seismic waves generated by earthquakes, and they may lead to additional earthquakes -- often long after the initial earthquake has occurred
This delayed reaction is still not completely understood, which is one reason why it was not fully accepted even a decade ago. In addition, seismic instrumentation only reached a point where dynamic triggering could be convincingly observed in the early 1990s. In the last few years, laboratory observations and simulations have become mature enough to begin generating the types of data needed to simulate conditions observed in the Earth. In Paris, Johnson will describe some of the observations and physical models that have been applied to try to explain how dynamic triggering might occur, noting what they are able to explain and what remains a mystery. Ultimately, the goal of this research is to contribute to more accurate forecasting of when and where future earthquakes are likely to occur. (Talk 2pPAa8, "Observations and Models of Dynamic Earthquake Triggering" will be at 6:00 p.m. on Tuesday, July 1, 2008 in Room 342B).
11) PROTECTING UNDERWATER ARCHEOLOGY
An estimated one million shipwrecks from ancient times litter the sea floor. A great portion of these sites are in relatively shallow water and can be approached with simple equipment including sonar, echo sounders, GPS navigation, and diving gear. What about the security of these sites? Archeology sites on land are pretty easily protected. Marine sites need more ingenuity. Tuncay Akal (firstname.lastname@example.org) of the SUASIS Underwater Systems situated at TUBITAK-Marmara Research Center Campus in Turkey describes an automated system which acoustically scans the underwater sound field in the vicinity of wrecks. This concept has been developed with the participation of scientists from France, Turkey, the United States, and the NATO Undersea Research Centre (NURC). The appearance of an unauthorized intruder triggers an alarm communicated to authorities by sensors on the sea floor, to a floating buoy above, and thence to a satellite link or directly to a base on shore (Talk 4pEAb2 "Surveillance and Protection of Underwater Archaeological Sites: Sea-Guard" will be at 1:20 p.m. on Thursday, July 3 in Room 342B).
12) ANCIENT BUILDINGS: GREECE, PERU, INDIA
Modern acoustical studies can help to recreate the sonic environment inside buildings hundreds or thousands of years old. Arturo Sevillano of the Univ. Politecnica de Valenica in Spain (email@example.com) reports on the likely vibrational modes of bronze vases stationed in various Greek and Roman theaters in such a way that they (through their resonant reaction to sounds from the stage) would make up for some of the acoustic deficiencies of the theater (talk 4pAAa5).
Paul Calamia and Jonas Braasch of Rensselaer Polytechnic Institute in the USA (firstname.lastname@example.org) report on the vibrational modes of the solid granite musical pillars found in some Hindu temples dating back as far as the 7th century. These pillars, often carved from a single piece of stone, were tuned by size and were "played" during certain ritual performances (talk 4pAAa6). Jonathan Abel of Stanford University in the USA (email@example.com) will discuss the acoustics of Chavin de Huantar, a site in Peru that ante-dates the Inca empire by 2000 years (talk 4pAAa8). Of interest is a series of underground galleries used for ritual purposes. The gallery architecture produces acoustics that adds an auditory dimension to the disorienting underground, maze-like environment. All three talks are part of a session on archeological acoustics that will be from 1:20 to 7:00 p.m. on Thursday, July 3 in Room 242B).
13) CLASSROOMS: HALLOWED HALLS WITH STUDENT-FRIENDLY WALLS
Students have enough difficulty concentrating in class without having to strain to hear the teacher. Not surprisingly, studies have shown that student performance is connected to the sound quality of the classroom. Although room acoustics can be improved by adding sound-absorbing materials, schools situated in historic buildings often prohibit these sorts of alterations.
Luigi Maffei (firstname.lastname@example.org) and his colleagues were faced with such a problem at the Second University of Naples. Both students and teachers complained about inaudibility in classrooms of the Faculty of Architecture, which is housed in a 16th century monastery. Audio measurements in eight classrooms determined that the reverberation time (i.e., the time it takes a sound to fade out) was more than one second, which is the above the limit set by several national guidelines.
Maffei's team looked at various ways to muffle the reverberations while respecting the centuries-old architecture. Traditional methods of placing mineral or glass fiber panels overhead were ruled out because of the high historical value of the ceilings. Permission was however given to install removable wall panels. For this purpose, the researchers tested various sustainable materials, such as hemp and cork, and found the best absorption came from panels made of kenaf, a fiber derived from a type of hibiscus plant. When the kenaf panels were installed in several classrooms, measurements of speech intelligibility improved from "poor" to "fair." Such low-impact acoustic remedies might benefit other historically-set universities. (Talk 5pNSa1, "Are classrooms in historical buildings compatible with good acoustics standards?" will be at 2:00 p.m. on Friday July 4, 2008 in Room 242A).
14) DIALECT FORMATION AND MEXICAN-AMERICAN IDENTITY
When two language groups meet in bilingual communities, how do new dialects emerge out of the conflation of cultures and communication needs? The answer is hardly straightforward. But a novel application of acoustical analysis is helping to produce insights. When applied to analyzing four generations of speech in an established Mexican-American community in Pearsall, Texas, this analysis suggests a new approach to understanding the evolution of language varieties.
To evaluate the effects of two languages on each other in a community, Dr. Erik Thomas of the Department of English at North Carolina State University (email@example.com) applied quantitative analysis of variation in speech among speaker groups, a method known as sociophonetics. Linguists refer to the influence of the source language-Spanish, in this case-on how the incoming group speaks the target language (English, here) as a "substratal effect." Substratal effects can be obvious or subtle, and generally involve pronunciation and grammar more than vocabulary. Most studies of substratal effects in the formation of new language varieties do not combine acoustic sophistication, broad analysis of pronunciation features and statistical comparison of them among different generations of speakers. Dr. Thomas' unusual approach does.
By doing so, it provides evidence for how a synthetic approach can produce insights into both community and language formation. It also offers a means of understanding why some Spanish language features are discarded, while others are conserved. Still other Spanish language features create a life of their own as they become markers of Mexican-American identity. (Talk 1pSCb2, "Sociophonetic methods for studying substratal effects and new dialect formation" will be on Monday, June 30 at 1:20 p.m. in Room 250B).
MORE INFORMATION ABOUT ACOUSTICS '08 PARIS
The science of acoustics is a cross-section of diverse disciplines, including fields such as architecture, speech science, oceanography, meteorology, psychology, noise control, physics, marine biology, medicine, and music. Acoustics'08 Paris is the world's largest meeting devoted to this range of topics. It incorporates the 155th Meeting of the Acoustical Society of America (ASA), the 5th Forum Acusticum of the European Acoustics Association (EAA), and the 9th Congrès Français d'Acoustique of the French Acoustical Society (SFA) integrating the 7th EUROpean conference on NOISE control (euronoise), the 9th European Conference on Underwater Acoustics (ecua) and the 60th Anniversary of the SFA.
MEETING WEBSITES OF INTEREST
ASA's WORLD-WIDE PRESS ROOM
ASA's World Wide Press Room will contain tips on dozens of stories as well as lay-language papers detailing some of the most newsworthy results at the meeting. Lay-language papers are roughly 500-word summaries written for a general audience by the authors of individual presentations with accompanying graphics and multimedia files. They serve as starting points for journalists who are interested in covering the meeting but cannot attend in person.
Around mid-June, ASA's World Wide Press Room (http://www.acoustics.org/press) will be updated with the new content for the Acoustics'08 meeting in Paris. A detailed release describing the World Wide Press Room will be sent out in late-June.
ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,500 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America-the world's leading journal on acoustics, Acoustics Today magazine, books and standards on acoustics. The Society also holds two major scientific meetings each year. For more information about the Society, visit our Web site, http://asa.aip.org.
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