How a JMU student's curiosity led to a fascinating research project

It all began when Zev Woodstock, a senior mathematics major, was on his way back from his intro to acoustics class during his sophomore year.

"I saw people laughing and clapping in the middle of this brick plaza [on the quad] and I walked up and asked, 'What are you guys doing?' and they said, 'Just clap, right there—stand there and clap.' And I did and was completely surprised—I had no idea what was happening," he said.

If you stand in the middle of certain brick plazas on campus and clap, snap or stomp, you can hear a high-pitched squeaking noise. Woodstock later found out that this phenomenon is called the "repetition pitch" effect.

"It happens at the center of the circular plaza on the quad in front of Wilson, and there are similar circular structures in front of Forbes, between Roop and Maury and at the sundial in front of Burruss," Woodstock said. "This effect happens at all of them. You have to stand right at the center and then you clap, snap, stomp, make some sort of percussive white noise, and then you hear this high-pitched squeaking sound in your ear." 

After asking Dr. Caroline Lubert about the noise, Woodstock began working on a class project about it that later turned into an independent study. Woodstock and Lubert, a professor mathematics and statistics who specializes in acoustics research, eventually collaborated on an expository paper about the effect that he presented at an annual meeting of the Acoustical Society of America in Indianapolis. 

"That was a great time," Woodstock said. "I actually got to meet one of the gentlemen that was one of my main sources . . . he walks up while I'm presenting my poster and said, 'Yeah, the effect is also psychoacoustic,' and I said, 'Oh that's interesting,' and he said, 'Yeah, by the way I'm that guy'—and he points at my works cited."

According to Woodstock's findings, the effect occurs because of how the bevels in the brick are structured. When someone claps, the sound radiates outward and reflects off of each brick bevel. A series of reflected pulses comes back toward the observer at an apparent frequency, and that frequency happens to be within the human hearing range. The reason the sound is so high pitched is because the space between the bricks is relatively small.

Woodstock's interest in math originally stemmed from his high school pre-calc teacher, and his experience at JMU further solidified his interest in the subject. "I came to JMU as an undeclared major, and I was in Dr. Paul Warne's Calc 2 class. He's a really fantastic professor—he just really showed me the cool things that you can do with math, the beauty you can get from discovering a new thing in math, that sort of stuff. It was the first time I saw that if you have the right professor, math can be really, really intriguing."

Dr. Warne gave Woodstock the motivation to want to become a math professor as well. "I am so thankful that I came here [to JMU], and especially ran into the math department because all of these professors really, really care about undergraduate education and also giving undergraduates research experience." 

Woodstock has participated in two REUs (Research Experience for Undergraduates), his most recent one at Texas A&M University this past summer. He will present his research this January at the Joint Mathematics Meetings in Seattle, the largest mathematics meeting in the world. "I just recently finished the last of two papers for my REU over the summer, so we've submitted that and I'm still in the presentation phase," he said.

The math department has supported Woodstock with various scholarships. He received the Lisa Persson-Helms scholarship his sophomore and junior years and currently has the Joan and Ernest Droms scholarship, a scholarship specifically reserved for seniors. "I was really thrilled to get that," he said.

According to Woodstock, getting into research is all about being proactive. He described the professors as "very warm, friendly people."

"You could just ask them about it and I'm sure they'd be happy to talk to you about it," he said. "Math research is kind of a lonely place, so if anybody gets an opportunity to talk about it, they love to share." 

Woodstock said that math research could be done almost anywhere. "A lot of the times it's just you and your research partner staring at a white board, thinking about your problem," he said. 

With a department full of supportive professors and an impressive amount of research experience, Woodstock is sure to find success in his future endeavors.

To learn more about Woodstock’s research, read his paper.

By Rachel Petty ('17), JMU Public Affairs