Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Short booms still annoying

19.10.2012
Scientists study how mid-level noise bursts lasting less than a second affect the concentration of arithmetic-solving test subjects

Noise can be distracting, especially to a person trying to concentrate on a difficult task. Studying annoying noises helps architects design better building environments and policy makers choose effective noise regulations.

To better understand how short noise bursts affect humans' mental state, researchers from the University of Nebraska – Lincoln played quarter-second-long white noise clips to test subjects as they worked on arithmetic problems.

The researchers noticed a slight general trend toward lower performance when louder noises were played, and also identified sound level ranges that caused participants to report significant levels of annoyance. The researchers report their findings at the 164th meeting of the Acoustical Society of America (ASA), held Oct. 22 – 26 in Kansas City, Missouri.

The motivation for the research came from NASA's low-boom supersonic aircraft program. Sonic booms, generated when aircraft traveling faster than the speed of sound leave cones of compressed air in their wake, are loud and potentially unnerving. In 1964, when the Federal Aviation Administration starting flying supersonic jets regularly over Oklahoma City as part of a test called Operation Bongo, many citizens filed complaints and damage claims. NASA is now working on developing aircraft that create softer booms, but is it not clear at what volume regular booms, as might be created by commercial supersonic aircraft flying over land, would be acceptable.

Lily Wang, an architectural acoustician at the University of Nebraska – Lincoln, worked with her graduate student Christopher Ainley to design an experiment to test how noise bursts affect the performance and perceptions of test subjects. Previous studies had looked at loud noises of more than 80 decibels (dB), louder than an average vacuum cleaner, and found a clear effect on subjects' ability to solve arithmetic problems. Wang and her team reduced the volume to see if they could find a threshold value under which the noise would not significantly affect the participants. Twenty-seven test subjects were asked to memorize 6-digit numbers, and then, when shown a 4-digit number, the subjects had to subtract the second number from the first number in their heads and type the answer on a keyboard. Occasionally the researchers would play a quarter-second burst of noise while the second number appeared on the screen.

The researchers tested noise bursts in the range of approximately 50 – 80 dBA. The dBA unit indicates that the volume was measured with a filter used to approximate the human ear's response to sound. The noise levels were comparable to about the sound level on a suburban street corner at the low end, to vacuum-cleaner loud at the high end. While the test subjects solved a lower percentage of problems correctly when interrupted with a noise at the louder end of the spectrum, the difference was not enough to be statistically significant. However, there was a significant difference in the levels of annoyance that the participants reported when quizzed afterwards about their perceptions of the noise environment. "The test subjects sort of adjusted to the quieter booms, but the louder ones remained jolting," says Wang. "This suggests that the acceptable noise from sonic booms should not be higher than 70 dBA once it gets inside the house."

The researchers' lab did not have the necessary equipment to mimic the very low-frequency component of the noise produced by sonic booms, Wang notes, but the work helped to quantify the effect of the short duration characteristic of the booms. As a next step, the researchers hope to study perceptions of the rattling component of noise that is often associated with supersonic jets passing overhead.

###

MORE INFORMATION ABOUT THE 164th ASA MEETING

The Kansas City Marriott Downtown Hotel is located at 200 West 12th Street, Kansas City, Missouri, 64105. The hotel main numbers are: 816-421-6800; fax: 816-855-4418.

USEFUL LINKS

Main meeting website: http://acousticalsociety.org/meetings/kansas_city
Meeting Abstract Database: http://asa.aip.org/asasearch.html
Hotel site: https://resweb.passkey.com/Resweb.do?mode=welcome_ei_new&eventID=8120158
WORLD WIDE PRESS ROOM

ASA's World Wide Press Room contains additional tips about newsworthy stories and with lay-language papers, which are 300-1200 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio, and video.
PRESS REGISTRATION

ASA will grant free registration to credentialed full-time journalists and professional freelance journalists working on assignment for major news outlets. If you are a reporter and would like to attend, contact Charles E. Blue (cblue@aip.org, 301-209-3091), who can also help with setting up interviews and obtaining images, sound clips, or background information.

This news release was prepared for the Acoustical Society of America (ASA) by the American Institute of Physics (AIP).
ABOUT THE ACOUSTICAL SOCIETY OF AMERICA

The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 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, ECHOES newsletter, books, and standards on acoustics. The Society also holds two major scientific meetings each year. For more information about ASA, visit our website at http://www.acousticalsociety.org.

Charles E. Blue | EurekAlert!
Further information:
http://www.aip.org

More articles from Physics and Astronomy:

nachricht Neutron star merger directly observed for the first time
17.10.2017 | University of Maryland

nachricht Breaking: the first light from two neutron stars merging
17.10.2017 | American Association for the Advancement of Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>