UC Engineers Speak Up about Harmful Noise

Engineers are often thought of as the brains behind large machinery such as cars, planes and industrial equipment. What is less often considered is the technology needed to keep these roaring creations from bursting an ear drum.

Researchers at the University of Cincinnati College of Engineering and Applied Science (CEAS) are working hard to effectively reduce loud, potentially harmful noises produced by large vehicles and equipment.

Active Noise Control (ANC) algorithms are a critical solution to the deafening noises. CEAS researchers Tao Feng and Guohua Sun are utilizing these mathematical equations to further safety in noisy environments. They will give presentations on their work at an upcoming research conference.

TAO FENG'S RESEARCH

Tao Feng is a student researcher advised by Dean Teik C. Lim. His paper titled “Fast Active Noise Equalizer Based on Inverse Model LMS Algorithm,” revised by post-doc fellow Gouhua Sun, focuses on active sound quality control (ASQC) used to control sounds that are more constant, such as an engine.

Feng explains, “The conventional ASQC for harmonic noise applies the active noise equalizer (ANE) and can reshape the harmonic components of a noise signal that can yield a better sound quality.” This means ASQC recreates the original sound making it less harmful or abrasive. Issues can arise with the secondary path dynamics (the path from the loudspeaker to the error location), effecting the speed at which the sound can be equalized, or made more suitable for human ears.

Feng says, “To overcome this limitation, a fast active noise equalizer system is proposed, which will eliminate the effect of the secondary path dynamics. It can be used in the vehicle for tuning sound quality. For example, when a driver accelerates a vehicle, this system makes the engine sound more powerful and smooth; when vehicle is on the highway, this system can make the engine quieter.”

Feng will present his paper at the 2014 Noise-Con conference in Fort Lauderdale, Florida. As a result of his impressive research, Feng is one of 10 recipients of the 2014 Hallberg Foundation Award which provides $500 for travel support. This new award enables undergraduates and graduates who are presenting at Noise-Con to travel without the burden of costly airfare.

“I am delighted, excited and deeply honored to be chosen for this award,” says Feng who is a first-time award winner and presenter for Noise-Con. The student researcher previously attended Noise-Con 2013 held in Denver, Colorado, and worked as a volunteer.

Tao Feng is grateful for the opportunity to present at the national conference and extends his gratitude to all those who helped him along the way. “I would like to thank my research advisor, Teik Lim, for giving me the opportunity to be introduced to the field of active noise control. I thank him for helpful guidance, advice and patience. Also, I would like to express my appreciation to Guohua Sun and Mingfeng Li for helping me to read and revise my paper.”

GUOHUA SUN'S RESEARCH

Sun, who also will be presenting at Noise-Con 2014, has focused his research in the area of repetitive or impulsive noises, unlike the constant hum of a vehicle. His latest research is a continuation from his dissertation titled “Active Control of Impact Acoustic Noise.”

Sun explains, “This Noise-Con 14 paper is targeted to develop an ANC system for many industrial noise issues showing repetitive impulsive and/or impact characteristics. For example, noises radiated from punching machines and pile drivers possess this impulsive characteristic. This type of noise is often transient in nature and typically sudden and instant high-intensity, which tends to cause more harm to human hearing than stationary noises (i.e. vehicle engine noise).” His work will help to reduce the harm of repetitive noises found in large factories and workshops.

Sun is the recipient of the 2014 Michiko So Finegold Award which also supports presenters with travel assistance. Sun says, “I am very glad to be one of the award recipients in this year’s Noise-Con, and really grateful for the support and acknowledgement from INCE foundation and the endowment from the Michiko So Finegold Memorial Trust to make this award available.”

Sun is no stranger to Noise-Con, having attended the past three years. At Noise-Con 2011, in Portland, Oregon, Sun presented his paper titled “Active transfer path control of substructure system with weak nonlinear coupling.”

Sun won the Best Student Paper at Inter-Noise 2012, in New York City, for his paper titled, “Modified Filtered-x LMS Algorithm for Active Control of Vehicle Road Impact Noise.”

Most recently, in Denver, Colorado, Sun attended Noise-Con 2013 where he presented his paper titled, “Experimental Investigation of Convergence Behavior of Modified FXLMS Algorithm for Impact Noise Control.” Also, Sun presented an overview of a 1953 paper on “Electronic Sound Absorber” in the “Old Meets New and Noise Control Education” session and received the only award for the best presentation.

Sun also extends his thanks to supervisor Lim. “I would like to express my sincere gratitude to my supervisor Dean Lim for offering me the opportunity to get involved in the field of active noise control. His insightful suggestions and guidance throughout this research work are really appreciated.”

Whether it be the loud roar of an engine or the sharp ping of a factory machine, Feng and Sun are working hard to ensure all workers are protected from dangerously loud environments.