Temperatures and wind conditions move traffic noise

May 25, 2011 by Deborah Braconnier report
traffic

(PhysOrg.com) -- Imagine sitting down for your early morning coffee when your nice little suburban morning is disrupted by the sound of highway traffic from a quarter mile away. When you purchased your home far from the freeway, the last thing you expected to hear was the roar of traffic, but according to a new study presented at a meeting of the Acoustical Society of America, Nick Ovenden from University College London says that is exactly what can happen when the right temperatures and wind conditions are present.

Ovenden worked with an Arizona team to investigate reports from some local Scottsdale, Arizona residents that had been hearing loud noises during the early morning and dusk hours. These residents lived a third of a mile away from the closest highway.

By using measurements of sound levels, and direction, and temperature, the team inputted the information into models of noise, including the prism-like effects that wind and temperature can have on .

What they discovered was that under the right conditions of crosswind and , sound that would normally go vertical is refracted back down. The reason this occurs most often in the early mornings and at dusk is because sound bends from hotter air to cooler air.

At these locations in Scottsdale, the team was able to record sounds as high as 67 , which, if it lasted an hour or longer, is above what the U.S Federal Highway Administration allows without requiring that noise abatement be created. While Ovenden did not record the noise for over an hour, he does say that under the right conditions, it would be possible.

While any type of meteorological effect is currently not being used with highway noise models, Ovenden believes this information shows that it should be considered when planning a new highway in order to determine just how bad noise could be in certain areas.

Explore further: New terahertz device could strengthen security

More information: Research paper: Impact of meteorological conditions on noise propagation from freeway corridors, J. Acoust. Soc. Am. Volume 126, Issue 1, pp. 25-35 (2009) asadl.org/jasa/resource/1/jasm… 5_s1?isAuthorized=no

via Discovery News

Related Stories

Is your convertible damaging your hearing?

Jan 09, 2011

Driving convertible cars with the top open at speeds exceeding 88.5 kilometres per hour (55 miles per hour) may put drivers at increased risk of noise-induced hearing loss, according to new research published in The Journal ...

Living under a flight path increases heart attack risk

Oct 12, 2010

(PhysOrg.com) -- Research in Switzerland suggests the risk of dying from a heart attack is greater for people exposed to the noise of aircraft flying overhead. The study included data on 4.6 million adults ...

Finding a Better Way to Quiet Noisy Environments

Apr 05, 2006

Researchers at UCSD report in the April 4 issue of the Journal of Sound and Vibration a new mathematical algorithm designed to dramatically improve noise-cancellation technologies that are used to quiet everything from a ...

Recommended for you

New terahertz device could strengthen security

Nov 21, 2014

We are all familiar with the hassles that accompany air travel. We shuffle through long lines, remove our shoes, and carry liquids in regulation-sized tubes. And even after all the effort, we still wonder if these procedures ...

CERN makes public first data of LHC experiments

Nov 21, 2014

CERN today launched its Open Data Portal where data from real collision events, produced by experiments at the Large Hadron Collider (LHC) will for the first time be made openly available to all. It is expected ...

New technique allows ultrasound to penetrate bone, metal

Nov 20, 2014

Researchers from North Carolina State University have developed a technique that allows ultrasound to penetrate bone or metal, using customized structures that offset the distortion usually caused by these ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

nanotech_republika_pl
not rated yet May 25, 2011
Does the same thing happen before a storm? I thought it was due to the increased air moisture and maybe low air pressure.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.