The 159th meeting of the Acoustical Society of America (ASA) will be held jointly with NOISE-CON 2010, the 26th annual conference of the Institute of Noise Control Engineering (INCE-USA) from April 19-23, 2010 at the Baltimore Marriott Waterfront Hotel in Baltimore, MD.

Many of the presentations at the joint meeting will spotlight noise -- from its detection and measurement to its effect on people and animals in the wild to the latest policies and legal standards governing noise and innovative ways to control it.

NOISE-RELATED HIGHLIGHTS FROM JOINT MEETING

The following are just a few of the meeting's many interesting noise-related talks. Aviation Engineering: STIFLING THE SONIC BOOM

City Noise: IDENTIFYING THE SOUNDS OF CRISIS

Human Noises: SOUND LEVELS IN THE ARCTIC OCEAN

Community Noise Mitigation: PUBLIC OUTREACH WORKSHOP

Noise Inside a Car: QUIET CONCRETE ROADS

Construction Noise: "NO RACKET" JACKET FOR JACK HAMMER

Signal Processing: NOISE FILTERING FOR THE HEARING IMPAIRED

Noise in Healthcare Settings: NEW LEGAL STANDARDS

More Highlights -- OTHER INTERESTING SESSIONS

More Information for Journalists 1) Aviation Engineering: Stifling the Sonic Boom
SONIC "PUFF" TECHNOLOGY MAY SPEED SUPERSONIC FLIGHT OVER LAND

For the last 40 years, commercial aviation has hit a speed barrier in regulations prohibiting supersonic flight over land. These aim to limit the negative impact of loud sonic booms on populated areas, and current regulations permit commercial supersonic flight only over oceans, significantly limiting the speed benefit from supersonic flight. New aircraft configurations are emerging that are shaped to minimize the shock waves associated with sonic booms and may allow supersonic speed over land.

"Commercially, supersonic flight has been a flop because [planes] couldn't fly over land -- the booms were just unacceptable," explains Dr. Kenneth Plotkin, chief scientist with Wyle in Arlington, VA, an expert on sonic booms who will present the current research on low-boom, high-speed aircraft design.

The key to the new aircraft is the modified body shape, Plotkin explains. "You can eliminate the intrusive part of the boom by properly shaping the craft, because this changes the evolution of the boom as it propagates," he says.

The new design alters the interaction of nose and tail sound waves that famously and loudly meet in shock waves at supersonic speeds to produce the explosive sonic boom. Instead of generating what are known as "N-waves" -- typical of conventional aircraft that produce unacceptably large shock waves -- aircraft shaped for a low-boom minimize shock waves to an acceptable level of loudness. They may still be audible as they fly over populated areas, but these planes would produce a sonic "puff" as opposed to a sonic boom.

"Low-boom shaping technology is within grasp, and it has significant potential to change the culture of flight over the next 10 years," Plotkin says. He estimates that they first commercial application of the new design will be supersonic business jets that will emerge within the decade and carry 6-10 passengers, traveling at speeds up to Mach 1.8 between New York and California and arriving in just under 3 hours -- about half the current travel time.

Talk #1aNCa1, "Sonic boom: From bang to puff" is at 8:05 a.m. on Monday, April 19.

2) City Noise: Identifying the Sounds of Crisis
ACOUSTIC AND SEISMIC SENSORS IN BALTIMORE HELP SORT COMPLEX CITY SOUNDS

Beeping, shouting, construction, the sounds of tires on roads, and other loud noises -- all partly masked by mazes of tall buildings -- make up the fabric of the modern urban soundscape. To urban sound sleuths such as Donald G. Albert, a scientist with the Engineer Research and Development Center (ERDC) Cold Regions Research and Engineering Laboratory, in Hanover, NH, this complex soundscape is a challenge. He is tasked with developing a way to use sensors to sort out the complex bounce of signals, noise, scattered sounds, echoes, and vibrations in urban environments.

Acoustical sensors (which monitor sound) and seismic sensors (which are sensitive to vibrations) have great potential for monitoring urban sounds and human activities, says Albert. "But to fulfill this potential," he says, "sensor algorithms must be designed to reliably identify signals of interest -- and to also cope with environmental effects, including high levels of background noise often found in urban areas."

Albert recently made a series of seismic and acoustical measurements in Baltimore, which he will be presenting next month. These measurements are helping him create computer algorithms to select certain signals out of the city noise. The goal is to implement sensors to gather sound remotely and use these algorithms to interpret the sound and predict activity it suggests so that timely responses can be made.

The applications are numerous, says Albert. Neighborhoods may be able to pinpoint the sources of offensive noises. Hospitals may use remote systems as early-warning systems, helping them prepare the ER staff for traffic disasters. Security firms may be able to detect idling engines or other subtle noises, allowing them to keep a remote watch on guarded properties. And local police or military forces may be able to look for certain sound signals that would help them avert or respond to attacks or disasters.

Albert's urban sound data are interesting because they show unusual extremes: lower acoustic frequencies, down to 6 Hertz, compared to the human hearing range of 100-10,000 Hertz - and higher seismic frequencies. Where a typical earthquake produces most of its seismic energy at low frequencies, usually below 1 Hertz, Albert's city seismic readings showed the strongest energy at higher frequencies between 6 and 100 Hertz.

"Our measurements reveal the interesting details of the noise produced by a city, and are helping to fill in a gap in the data so that we can advance the technology of managing sound in complex environments," he says.

Talk #1pNSc1, "Urban acoustic and seismic noise measurements in Baltimore" is at 1:30 p.m. on Monday, April 19.

3) Human Noises in the Arctic
LOSS OF POLAR ICE INCREASES BOAT TRAFFIC AND SOUND LEVELS IN ARCTIC OCEAN

With the melting of polar ice, never before in modern life has so much open ocean water been accessible in the Arctic. And where there's water, there is opportunity for commercial shipping, and where shipping lanes emerge, big boats -- and big noise -- may follow.

According to John Farrell of the U.S. Arctic Research Commission in Arlington, VA, increased traffic from commercial fishing trawlers, zinc ore boats, oil and gas exploration rigs, sea floor mapping vessels, and tourist cruise ships are all contributing to the growing noise burden of Arctic waters.

While the Arctic Ocean is certainly a naturally lively acoustic environment -- from ice and wave action to whale song -- the animals and people who live there have adapted to these sounds over millennia. What is of interest to scientists like Farrell is the expanding potential for acoustic impact from human noises -- engines, propellers, explosive seismic airgun arrays used in geologic exploration, and other potentially disruptive sounds.

"Suddenly, we're adding all these new noises, but we're not clear on what the impact will be to the marine mammals, and to the people who live in the Arctic," he says. "The United States has begun the baseline oceanographic research necessary to support national and international goals for ecosystem-based management and marine spatial planning in the Arctic Ocean, but there's a long way to go."

For example, Farrell notes that scientists have only a limited understanding of the effects of increased noise on seal, walrus and whale behavior. More boat traffic and noise may frighten the animals away from hunters, jeopardizing sources of food and cultural traditions.

"That's just one basic example of what needs to be studied and understood," Farrell says. In Baltimore, Farrell will outline new research being called for by the U.S. Arctic Research Commission, an independent federal agency that advises Congress and the Executive Branch.

Talk #1aAO1, "The accessible Arctic Ocean" is at 9:05 a.m. on Monday, April 19.

4) Community Noise Mitigation: Public Outreach Workshop
NOISE HAS A PROFOUND LOCAL IMPACT -- EVEN IF FEDERAL POLICY DOES NOT

Community noise is a major social problem that generally decreases the quality of life for many people in the United States, and it is continuing to grow -- especially in major urban areas. In cities like Baltimore, community noise causes a variety of problems for local residents -- from simple annoyances to profound negative impacts on human health.

"These problems will not be adequately addressed until the public demands that the government improves and updates our approach to noise mitigation," says Lawrence S. Finegold, Chair of INCE/USA Technical Committee on Community Noise.

Finegold says that the United States has not made many significant improvements in community and environmental noise policies, particularly at the national level, in several decades. Nor is there sufficient funding available for related research and technology, he says, even though the need for new research-based policy is great. "This includes expanding research on the effects of noise, measuring of overall community noise exposure, enacting adequate national, state and local noise policies, and improving effective and affordable noise control technologies," he says.

Now Finegold is launching a new effort to engage the public and obtain input on the noise problems people experience and what actions they would like to see implemented. The first step in this effort will be an April 19th Public Outreach Workshop on community noise in Baltimore that will also inform the public on the deleterious effects of community and broader environmental noise, provide information on noise mitigation options and discuss various noise policy issues and available approaches.

The workshop will include a panel of prominent national speakers on community noise control who will make presentations on a variety of topics faced by residents of Baltimore, including the noise situation in Baltimore, desired local government responses, the Baltimore noise ordinance, the Maryland noise control regulation, and the role of federal, state and local governments in addressing community noise issues. The Workshop will also give the first brief overview of a forthcoming National Academy of Engineering study titled "Technology for a Quieter America," which will be published later this year.

The Public Outreach Workshop on Community Noise will take place from 1:30 until 5:00 p.m. on April 19, 2010 in the Atlantic Room of the Baltimore Marriott Waterfront Hotel.

5) Noise Inside a Car
QUIET CONCRETE PAVEMENT IS KEY TO MORE QUIET RIDE

The stereo test tells all: You're in the driver's seat, buckled in, mirrors adjusted, traffic checked, in gear. Rolling. Cue the sound system, crank the volume, and crank it again. And then crank it again. This simple diagnostic is revealing: If you have to keep turning your stereo up as you drive to hear the music, you likely have "noisy pavement" under your tires.

"Most people think engines are responsible for most of the noise driving, but that's not true for passenger cars," explains engineer Robert Otto Rasmussen, P.E., of The Transtec Group, Inc. in Austin, TX. "The biggest source in most cases comes from the interaction between the road surface and the tires."

His analysis of five years' worth of comprehensive data from hundreds of concrete pavement surfaces shows that resurfacing old noisy concrete with a technique called diamond grinding yields excellent results in terms of producing a high-friction concrete surface. The technique basically removes surface irregularities and restores the road to a smoother, safer, and more silent surface.

Rasmussen calls quiet concrete the ride of the future, but even though diamond grinding is a proven technique, he says that it has been slow to catch on. "It's very difficult to change mindsets, but diamond grinding can often serve the public better than other more traditional alternatives," Rasmussen says. He is optimistic that one day building roads in the United States will reach the level of sound sophistication it has achieved in certain European countries.

"In some European countries they classify both tires and roads by their noise potential, so you can buy a tire or build a pavement in part for its ability to produce a quiet ride," he says, adding that with quiet concrete pavements, the difference is immediately perceptible. "You simply don't have to reach for the volume to turn the radio up."

Talk #1pNCd3, "Quiet concrete pavement surfaces" is at 3:45 p.m. on Monday, April 19.

6) Construction Noise
QUIETING THE SOUNDS OF PROGRESS -- THE "NO-RACKET JACKET"

New York City is constantly maintaining, repairing, and reinventing itself, ongoing work that creates a lot of construction noise. However, a collaborative team including the New York City Department of Environmental Protection (DEP), consultants, utilities and an equipment vendor are working together to quiet the sounds of progress and improve the quality of life for those who live and work in the city. In furthering the city's commitment to reducing noise is embodied in a new noise code and new construction rules, the DEP team wanted to look at ways to eliminate jackhammer noise -- an annoyance for residents and businesses and an important occupational hazard for construction workers.

Studies show that the internal components of the jackhammer are a major source of noise and that they can be substantially quieted. DEP staff suggested a noise-muffling sleeve and reached out to a one of the city's utilities and a major vendor of industrial jackhammers used by utility workers and the construction industry. Development of the "no-racket jacket" began in 2006, and testing was conducted to demonstrate its effectiveness. Made of multiple layers of neoprene-like material, jackets tested reduced jackhammer noise to within 1 decibel of the newly imposed noise level limits of 85 decibels. While limiting noise in the environment was the key motivation for the work, noise was also significantly reduced for the equipment operators, leading to an award to DEP and Parsons Brinkerhoff, a noise remediation firm, from The National Institute for Occupational Safety and Health (NIOSH), in partnership with the National Hearing Conservation Association (NHCA).

"This has been a real team effort," says Eric Zwerling, Director of the Rutgers University Noise Technical Assistance Center, who was involved in the work. "Innovative regulation can bring together diverse interested parties, and the tangible result is improving the quality of life for residents and workers."

Talk #2pNCa9, "Proactive regulation engenders creative innovation: Quieting the jack hammer" is at 3:00 p.m. on Tuesday, April 20.

7) Signal Processing: Noise Filtering for the Hearing Impaired
A SOLUTION FOR IMPROVING SPEECH INTELLIGIBILITY FOR THE HEARING IMPAIRED

Recall what it is like trying to focus on a conversation in a crowded and noisy bar -- and then imagine having to do this even in a relatively quiet room. This is exactly the challenge that faces many people who rely on hearing aids or have cochlear implants. While these technological advances make it possible for many to hear who would not otherwise, they do not allow the individual to filter out background noise.

Now, Philip Loizou at the University of Texas-Dallas is developing sophisticated algorithms to allow the microprocessors in these devices to filter noise in the same way the unaided normal human ear does. Noise-suppression algorithms in the past have been effective in improving speech quality, but have not improved speech intelligibility, particularly in noisy environments. In fact, many of the noise-suppression algorithms actually introduce speech distortion.

Thus far, Loizou has demonstrated significant improvement in speech intelligibility by using environment-optimized algorithms, i.e., algorithms that are "tuned" to a particular listening environment. This makes it possible for the listeners to filter out background noise and understand a conversation, even in a noisy environment. This study involved both normal hearing and hearing impaired subjects. Lab results have been very promising, and the next step is the testing of these new algorithms in a real-world environment. These advanced algorithms and their application could mean a significant difference for hearing impaired individuals who rely on hearing aids and cochlear implants to hear the world around them, without having to hear the whole world.

"This work could make it possible for hearing-impaired listeners to better communicate in the noisy environments that are part of everyday life," Loizou says.

Talk #2aSC1, "Noise-suppression algorithms for improved speech intelligibility by normal-hearing and cochlear implant listeners" is at 8:05 a.m. on Tuesday, April 20.

8) Noise in Healthcare Settings
NEW ACOUSTICAL STANDARDS PRESENT BOTH CHALLENGES AND OPPORTUNITIES

A pair of new documents on healthcare acoustics, which have just been released after five years of peer review and public comment, are described by one of their authors as both a carrot and a stick. They set measurable minimum acoustical standards for the health care industry, and because these new standards have already been adopted by the Leadership in Energy and Environmental Design (LEED) Green Building Rating system, they are the basis for two new Environmental Quality credits. Because of Health Insurance and Portability Act (HIPAA) rules and new conditions imposed last November by Obama's ARRA HITECH Act, there are serious fines (up to $1.5 million) for non-compliance.

"We set out five years ago to make effective, comprehensive, comprehensible, and enforceable public policy across the broad spectrum of acoustics in the $1.4 trillion U.S. healthcare industry," says David Sykes, who co-chaired the ANSI S12 WG44 group that drafted the document -- along with Greg Tocci. "Now we are at the beginning of a new era for the staff of healthcare facilities in this gigantic industry who will need extensive help from acoustics professionals in complying with the new criteria," Sykes adds.

One document, titled "Sound & Vibration 2.0" outlines the comprehensive reference standards on sound and vibrations in health care facilities. It includes construction advice for engineers, reference tables, case studies, and useful data.

The second document is the "2010 FGI-ASHE-AIA Guidelines for Design and Construction of Healthcare Facilities," which is accepted as building code by over forty-two states, seven federal agencies and several foreign countries. Known as the "architect's bible" in healthcare design, the book is revised and issued every four years and is the only general document needed by those involved in the planning, design, construction, operation, and renovation of any type of licensed healthcare facility. The 2010 edition is the first to include comprehensive acoustical criteria for all aspects of community and interior noise, sound systems, speech privacy and building vibration.

Talk #2aNSc11, "Strengthening the healthcare guidelines: About the new online research community" is at 11:40 a.m. on Tuesday, April 20.

Talk #2pAAa1, "Speech privacy: The new 2010 architectural guidelines" is at 1:00 p.m. on Tuesday, April 20.

9) MORE HIGHLIGHTS -- OTHER INTERESTING SESSIONS ON NOISE

In addition to the highlighted talks above, there are many other interesting noise-related talks and sessions at the meeting -- some of which are listed below. For a complete list of abstracts for any of these sessions, go to the searchable index for the 159th Meeting (asa.aip/asasearch.html) and enter the session number with asterisk (e.g., 1aNSa*).

MONDAY Rocket Noise (1aNSa*) 8:00 a.m. - noon

Noise-Induced Hearing Loss (1aPP*) 8:00 a.m. - noon

Community Noise (1pNCa*) 1:00 p.m. - 3:15 p.m.

Noise and its Control in Complex Urban Environments (1pNSc*) 1:00 p.m. - 3:15 p.m.

Wind Turbine Noise (1pNSd*) 1:15 p.m. - 2:40 p.m.

Industrial and Power Plant Noise (1pNCb*) 3:30 p.m. - 4:45 p.m. TUESDAY Automotive and Powertrain Noise and Vibration (2aNCc*) 9:15 a.m. - 11:30 a.m.

Sound Propagation in the Atmosphere (2aNCe*) 10:30 a.m. - 11:45 a.m.

Heathcare Acoustics (2aNSc*) 8:00 a.m. - noon

Information Technology Noise (2pNCb*) 1:00 p.m. - 3:30 p.m.

Construction Noise (2pNCa*) 1:00 p.m. - 4:45 p.m. WEDNESDAY Aircraft Interior Noise (3aNCa*) 9:15 a.m. - noon

Noise and Vibration in the Mining Industry (3aNCc*) 9:15 a.m. - 11:45 a.m.

Military Noise Environments (3aNSa*) and (3pNS*), 8:05 a.m. - noon & 1:00 p.m. - 2:00 p.m.

Sonic Boom (3aPA*) and (3pPA*), 8:00 a.m. - noon & 12:45 p.m. - 3:25 p.m.

Primary and Secondary School Special Function Spaces (3aAA*) and (3pAA*), 8:00 a.m. - 11:00 a.m. & 1:00 p.m. - 2:20 p.m. The Baltimore Marriott Waterfront Hotel is located at 700 Aliceanna Street in Baltimore, MD 21202.

USEFUL LINKS:

Main meeting website: asa.aip/baltimore/baltimore.html

Full meeting program: asa.aip/baltimore/program.html

Source:
Jason Bardi
American Institute of Physics