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PROVO -- When you think of fighter jets or Gatling guns, it's the bullets and bombs that often come to mind as causing destruction. However, one BYU professor spends his time studying the sound waves that come from very loud objects, sound waves so powerful they can knock down walls and shake machines to pieces if they aren't properly constructed.
Assistant professor of physics Kent Gee enjoys playing musical instruments, and it was his interest in music that led him to study acoustics. However, the sound waves he often studies aren't the light tones of a harp or the smooth sounds of a violin. He's known as a specialist in sounds that could blast out your eardrums.
Gee was asked to study Gatling guns at Hill Air Force Base that end up getting mounted onto A-10 Warthog jets known as "tank killers." His job was to help design an indoor shooting range that can withstand the powerful sound waves that bounce around the walls.
In a previous shooting range that used smaller Gatling guns, the building had a hard time holding up.
"Over time the concrete walls were disintegrating, basically cracking from the blast pressures," said Gee. During tests they set up a plywood chamber that was 10 feet away from the gun to see if it could contain some of the sound waves.
"They fired the gun several rounds and it basically splintered the plywood."
Gee also noted that kind of pressure could tear up the inside of a human.
NASA is another group that came calling for Gee's ability to capture and study intense sounds. They asked him to analyze the sound coming from the plume of the rockets designed to power the next generation of U.S. spacecraft.
He said it took one set of tests at the ATK testing site at Promontory, Utah, just to figure out what kind of microphones could handle the pressure. Then further tests were used to capture the sound and map out how the sound was created and traveled.
"Once we get that information we can provide it to others and they can be looking at, well, how does that noise impact the launch pad environment, the payload. If it's a manned launch vehicle how does it impact the astronauts?"
As part of Gee's work he also gets to mentor students, including graduate student Alan Wall. Wall helped set up the testing when Gee was asked to map out sound waves coming from the back of F-22 Raptors at Hill Air Force Base.
A jet was tied down, the sound recording sensors put in place, and the afterburners were turned up full throttle.
"It was at one point so powerful that I had to turn my back on it. It was hard to face it and breathe easily. I felt more comfortable facing away from it but you could still feel those vibrations, said Wall.
Wall said the ultimate goal is to help protect the people working in and around the jets, as well as help the military use the information to make the jets run quieter and more efficiently.
When Wall and professor Gee are back at BYU they often spend time studying sound waves in one of the largest anechoic chambers at a University in the United States. The chamber is basically a large soundproof room that's built underneath the Eyring Science Center. The walls are covered in sound absorbing wedges and the floor is a wire mesh suspended 10 feet in the air so there are no echoes or reverberations inside.
"When you are in there by yourself, I mean it is extremely, extremely quiet," said Gee. "Your ears and your brain are just searching for something to listen to."
Over the years sound tests in the chamber have ranged from a military drone aircraft to finding the perfect position to place a grand piano for a concert.
Email: rjeppesen@ksl.com
