Sound Science: Assessing Acoustics in the Mezz
The next time you’re in the Mezz to hear a concert, comedian or speaker, take a minute to notice the undercurrent of noise competing for your ears — and your attention.
If you listen for it, you’ll hear the soft, steady hum of the water fountain cooler. The buzz of nearby vending machines and the echo of sound bouncing off metal light casings, floor-to-ceiling glass windows and tile. You’ll notice the whoosh of air flowing through exposed ductwork and the flurry of muffled conversation wafting up from Capital Court diners one floor below.
To the average person, this aggregate noise is a minor annoyance. For performers, it’s a symphony of distraction — competition for their audience’s full attention. But for senior Cameron Girard, a music technology major and physics minor, it’s a chance to do relevant research, fulfill his honors capstone requirements and improve the sound quality of an important student venue.
Working with faculty mentors Dr. Mark Lochstampfor, Conservatory of Music, and Dr. Patrick Shields, Mathematics, Computer Science and Physics, Girard completed an acoustic assessment of the Mezz and made a series of research-based recommendations to optimize the way sound moves through the space.
On a recent Friday morning, before most students had stumbled out of bed, Girard stood in the middle of an empty Mezz. He clapped, paused, measured and documented. Then he took a few steps, clapped, paused, measured and documented. Clap. Pause. Measure. Document. Again and again, he repeated the procedure to record the sound's audio decay time, also known as T60 time, which measures the time it takes for sound quality to decay enough to become inaudible.
“Ideally, we want to diffuse the sound, like you would in a studio. More absorption. Less reverb,” Girard explained.
Newly produced sound is considered early energy. But as sound travels through a space, it reverberates and becomes late energy, like an echo. The ratio of early energy to late energy determines clarity, and the index is different for speech — a reverb time of about .9 seconds is best — and music, which can be 1.4 seconds. In the Mezz, the T60 time is about 1.2, which leaves room for improvement. Anything outside of those parameters can make music sound out of synch or sloppy, and can make a speaker sound muffled, like he needs to enunciate better, creating a less-than-optimal experience for the audience and the performer.
Girard was one of 12 students who were awarded funding this year through the Boyd Fund for Undergraduate Scholarship. The Boyd Fund was established by Dr. Richard A. Boyd (’51, H’84), former University trustee, and Marye McPherson Boyd (’54) to promote scholarship among Capital students. Funding is competitive, and grants can be used to support supplies, books, software, equipment and even travel to major libraries, art galleries and science labs to enhance the work. Girard was able to take real-time acoustic measurements in the Mezz using a sound pressure level (SPL) meter he bought with the grant money, along with web applications on his iPad.
Modeling the Mezz
After collecting his samples, Girard used sophisticated modeling software to simulate how his recommendations would improve acoustics in the space.
“During the modeling phase of the consulting process, we do a low-frequency analysis and see how the treatments we would put into the space would react,” he said.
Girard's laptop screen displayed a rectangular image — a model of the Mezz — with a smattering of red, orange, pale blue and yellow spots stretched from corner to corner, each color representing a different value of sound flow, cancellation, pressure and absorption.
“Here we have the Mezzanine as it is right now, with not much sound absorption, and you can see this Swiss cheese effect,” Girard explained. “This gives us a really clear image of how uneven the frequency distribution is. This inconsistency is not what we want; we want a more equitable listening quality for everyone in the space.”
Transitioning to another screen, which displayed the colors in a tiered pattern — less red and orange, more blue and green, smoothly distributed vertically throughout the space — Girard explained this image models sound flow in the space after the addition of one of his recommended treatments — a curtain to absorb sound.
Based on these findings, Girard went on to develop a comprehensive acoustic assessment, improvement plan and cost analysis to address the needs of his clients — the students, speakers and musicians who perform or attend events in the space, who he interviewed up front.
This acoustic consultation is a process Girard first experienced as a summer intern at Walters-Storyk Design Group, a New York-based firm that designs top listening, recording and viewing environments around the world for clients like Aerosmith (Vindaloo Music), Alicia Keys (Oven Studios), Bob Marley, Bruce Springsteen, Celine Dion and many more. Fresh off his internship, Girard attended an event in the Mezz, and it sparked his idea for the project.
Supporting Student Ideas, Fostering Independence
From Professor Shields’ perspective, that’s the ideal impetus for undergraduate scholarship. Because when students generate their own ideas, the research becomes more than an academic exercise. Students have a vested interest in the work.
“Like with the best of these projects, Cam came to me. It was his idea. It’s something he’s passionate about,” Shields said. “My role has been to offer support, to write a letter for him to help obtain the Boyd grant so he could buy some equipment. But mostly, it’s about smoothing the way and providing access to the equipment and software he needs in the physics lab to run the simulation and model the space.”
Enabling students to do their own scholarship is the ultimate teaching and learning experience, Shields added, because it empowers students to apply classroom theories independently, helping them grasp the material, apply it to their ideas, learn something new and then share the findings.
“We’re trying constantly to get students to the point where they can go off and do this work by themselves,” Shields explained. “This is the first inkling of what they’re going to be doing when they leave here. If they want to learn something special, something different, something more, they’re going to have to do it by themselves. So to be able to foster that independence — that’s fun. It’s what scholarship’s all about. You go and learn something new and you present to the world something different.”
Capital’s 17th annual Symposium on Undergraduate Scholarship will take place Wednesday, April 10, and Girard’s will be one of more than 100 student presentations given. An additional 28 students will not be able to participate because they’ll be presenting their research in disciplines that span the University at the National Conference on Undergraduate Research, which will be held this year at the University of Wisconsin-La Crosse. This is the largest number of students and projects accepted for presentation national conference in Capital’s history.
The breadth and cross-disciplinary nature of Girard's research, like many of those presented at the symposium and at NCUR, reflects Capital’s emphasis on learning and communicating across fields to broaden understanding and to position students to transfer their knowledge and skills to solve problems in any environment.
“The science that underlies music technology is fundamentally physics. So, if Cameron can learn what’s beneath the surface of the tools he’s exposed to in music technology, then that makes him a much stronger candidate for future positions, and makes him a better practitioner,” Shields said. “It’s one thing to have software, to understand how to use it, or to have equipment and tools. But it’s so much better if you understand what’s beneath it — the science that creates the reverberations, the acoustical information — the engineering — that goes into it. Thinking across those boundaries and not just sticking to one area or the other — that’s key.”