PORTABLE NOISE MONITORING TECHNIQUE AIMS TO IDENTIFY AND MAP OUT NOISE POLLUTION

August Schiess, University of Illinois at Urbana-Champaign
09/01/2016
Urban noise is sometimes seen as merely a harmless annoyance for people who live near busy streets or train stations, but it can cause health problems such as sleep disturbance, hearing loss, hypertension, and heart-related diseases.

Arrays are mounted to the top of an electric vehicle to measure noise levels.
Arrays are mounted to the top of an electric vehicle to measure noise levels.
Researchers have therefore been seeking ways to understand and combat the rising levels of urban noise. A team at the Advanced Digital Sciences Center (ADSC) has developed a signal processing technique that measures urban noise through portable microphones secured to the top of a moving vehicle, enabling the creation of a wide-ranging map of noise pollution.

“With a comprehensive understanding of the levels and types of noise pollution in urban areas, we can then analyze this information to create well-designed soundscapes that can alleviate the bad effects of environmental noise on physical and mental human health,” said Cagdas Tuna, a postdoctoral researcher at ADSC, a University of Illinois research center in Singapore.

Current noise-monitoring techniques are built into microphones fixed to the ground—they only measure sound from that vantage point, making a city-wide noise map an incredibly expensive idea. However, with the team’s portable solution, sound can be measured in as many locations as possible in the neighborhoods travelled by the vehicle.

To gather acoustic signals, they mount a microphone arrangement on an electric vehicle—the quiet engine keeps it from interfering with other external sounds. While driving along, the sensors identify a variety of noises and can pinpoint the location of sounds in relation to the vehicle.

Advanced signal processing tools recover and generate the noise-sources into an acoustic map at multiple frequencies.

“We have developed several different acoustic imaging algorithms, based on the multiple-location measurement scheme, to generate 2D acoustic maps,” said Tuna, a University of Illinois alumnus in electrical and computer engineering. “The maps show the noise-levels and locations of dominant noises.”

The team has been testing the new technique on Singapore streets over the past year. Tuna, who presented this work at the 23rd International Congress on Sound & Vibration (ICSV23) in July 2016, will continue to develop this technique by collecting more measurements around noisy areas such as construction sites.

This acoustics team at ADSC working on the project includes CSL and ECE Professor and ADSC Director Doug Jones, Tuna, Shengkui Zhao, ADSC research scientist, and Thi Ngoc Tho Nguyen, ADSC Senior Software Engineer.

Source : http://adsc.illinois.edu/news/