Spy planes, rockets, exploding balloons, fighter jets, Gatling guns, horns, and gongs. The Acoustics Research Group (ARG) at BYU has all the elements of a Hollywood blockbuster — only better, because it is all real.
Thanks to the state-of-the-art research facilities on campus, students of all levels are able to get directly involved in the science of acoustics. In addition to a variable acoustics chamber, the Eyring Science Center houses two anechoic chambers. The larger chamber is covered in giant fiberglass wedges, which absorb sound and isolate the source. Students place their research subjects, including small military spy planes and large Balinese gamelan gongs, in the chamber by walking out onto a wire net that serves as a suspended floor. An array of thirteen precision microphones is then used to take measurements.
Most recently the chamber has been the testing site for explosive balloons. Undergraduate students Julia Vernon and Michael Muhlestein tested the sound levels of hydrogen-oxygen balloons, which are commonly exploded in chemistry class demonstrations. The results of their tests may result in the modification or elimination of these demos, since the explosion was found to be louder (and more harmful) than jet noise.
Students also have access to two reverberation chambers. Rather than absorb sound like the anechoic chambers, these rooms are used for experiments requiring a prolonged echo. The high ceiling and hanging glass sheets allow for the sound of a single hand clap to continue for nearly nine seconds.
This room was recently utilized by student Matt Shaw and faculty member Kent Gee, who studied the sound of Gatling guns, forerunners to the modern machine gun. Their research provided crucial information needed to improve current testing facilities.
On top of all the action, the ARG is one of the leading acoustics research programs in the nation. Both graduate and undergraduate students can pursue individual research projects according to their interests, leaving them well-qualified to enter diverse fields. Support is provided by full-time faculty members from the Department of Physics and Astronomy, as well as the Department of Mechanical Engineering.
The group also serves as the BYU student chapter of the Acoustical Society of America (ASA). Alan Wall, president of the chapter, said participation in the group has given him the chance to meet with professionals and discover where he wants to go.
“As far as the group goes, the greatest benefit is the exposure to a lot of fields,” he said. “There is research on rockets and horns and pipes. Lots of the principles cross over, so it helps me to learn to do my own thing. I get to be involved more so than ever before. I’m in cutting edge research.”
Wall entered the PhD program after overhearing a professor at Utah State mention applying the principles of holograms to acoustics. Using some creative thinking and mathematical manipulation, he is now working on an original application of those ideas to jet noise at Hill Air Force Base, an opportunity made available through the ARG.
For students who are still just exploring options, the group holds weekly meetings to discuss basic concepts of acoustics, usage of equipment, and current research. Any interested student is welcome to come.
Jarom Giraud, a graduate student in the program, was offered research as an undergraduate after he began dropping in on the weekly meetings. He said he appreciates the diversity of research available in the program.
“There is a great opportunity to be published in acoustical journals because there is so much going on,” he said.
As members of the group, Wall and Giraud also participate in outreach activities, such as offering tours of the facilities. Wall said these types of events educate the public and also give those new to the field a chance to practice talking about their research on a general level.
This year, the ARG will celebrate the 50th anniversary of the ARG, which was originally started by BYU professor Harvey Fletcher, who was also one of the founders of the ASA in 1929. In the fall, the Erying Science Center will feature demonstrations and displays of Fletcher’s equipment, much of which he built himself. Wall said he looks forward to honoring Fletcher’s many contributions to the field.
“His research itself [in audio and musical acoustics] doesn’t have a lot to do with what I’m doing now,” he said. “But I’ve crawled up above the chamber, and I’ve seen his equipment. It has given me an appreciation for the equipment we have. Now, we can do in minutes and days what took them weeks and months. I can see how far we’ve come.”