On a Saturday in January, kids, teens, and adults gathered at the Bell Museum in St. Paul. They wandered between stations and bounced light off drums, looked at the waveforms created by an electric razor, and experimented with how they might hear if their ears were on backwards.

It was all part of an event called The Science of Sound, which provided participants with new understandings of the physics behind sound, the biology of hearing, and the history of audio recording. And St. Olaf College was well represented, with three faculty members — Associate Professor of Biology Norman Lee, Associate Professor of Psychology Jeremy Loebach, and Visiting Assistant Professor of Physics Eric Hazlett — providing lively scientific demonstrations on sound.

“Science is not just something in a laboratory, but something that you can interact with every day and all around us,” says Hazlett. “The set of experiments we had were just to play around and help people realize that play actually leads to — and can inspire — science.”

Lee’s demonstration, called Ear of the Beholder, helped participants to think about how sounds are perceived by animals. An animal’s hearing is influenced by its surroundings; a bird needs to be sensitive to different frequencies of sound than a fish would, making different animals’ perceptions of sound different from humans and different from each other. Along with four researchers in his lab — Post-Baccalaureate Research Associate Jimena Dominguez, Hong Quang Vu ’25, Jackson Gilbert ’25, and Aryan Khilari ’25 — Lee developed an app that guided users through a series of noises and animal sounds , prompting them to guess which animal could hear each sound.

“These animals see and hear and sense things differently than we do. Creating this Ear of the Beholder activity and having other people try it out is a way for others to experience that immense world,” Lee says. “I think it is important for us to translate our scientific research work on hearing to reach out to the general public.”

Lee’s collaboration with the Bell Museum began when he was applying for the National Science Foundation (NSF) CAREER award that he received in 2022. He has plans to develop a portable educational module, in collaboration with Professor Mark Bee at the University of Minnesota and his graduate student Katie Krueger, that could teach the public about the science behind animal hearing. The Ear of the Beholder app is the first iteration of this project.

The Science of Sound event was also an opportunity for researchers in the Lee Lab to explore science outreach and share their work with people of all ages off the St. Olaf campus.

“I think it’s important, especially for kids, to learn about something that they’d never thought of, but also to get a peek inside of the animal world and try to figure out why animals hear so differently than humans do and other animals do. That gives them more perspective and allows them to think creatively,” Dominguez says.

Ultimately, Lee’s lab hopes to turn their demonstration into an interactive booth that could be shared with nature centers in the Twin Cities area and other museums across the country. Lee is collaborating with St. Cloud State University Associate Professor of Graphic Design Haeinn Lee on the visual design of the interactive module. Lee’s lab also worked with Kreuger to examine how the app could be used in classrooms to meet Minnesota learning objectives, and they are working to develop an app that could be used in classroom science education.

Hazlett’s demonstrations focused on the physics behind sound waves. He brought a variety of setups, including ones that let participants see the shape of a waveform and create standing waves by connecting a piece of string to a razor and watching how the vibrations traveled along the string. He also demonstrated how sound waves can be transmitted in the form of light and detected using solar panels.

“Most of us are really intimately involved with sound in our everyday lives. Learning about how we interact with it and how it propagates and what makes a wave go back and forth can be a lens to start thinking about making other connections,” Hazlett says.

All of the activities Hazlett brought to the event were designed by physics students as a part of the Physics 232 course on waves and oscillations. Each year, students create demonstrations to present at Greenvale Elementary School. Over time, their creations are reused and refined, creating a library of projects for future outreach events. This spring, students will have the chance to present many of the same projects from the Science of Sound event at elementary schools in the area.

Loebach’s demonstration focused on how our brains determine the location of a noise. When locating the height of a sound, we rely on the unusual shape of the pinna, the visible part of the ear. The bumps and grooves of the ear filter out some sound wave frequencies. However, the filtered frequencies depend on the elevation of the sound, allowing the brain to identify whether a sound is coming from below us or above us. When locating a sound from left to right, we are able to compare how long it takes to arrive at each ear — a sound far to one side would reach the closest ear faster, while a sound directly in front of a listener would reach both ears at roughly the same time.

Loebach used boxes of Nerds candy to demonstrate the importance of the pinna structure in hearing. Participants were easily able to identify the location of a shaken candy box when listening normally. However, when they cupped their hands backwards over their ears, requiring sound to travel backwards over the pinna to be heard, they struggled to tell whether sound was coming from above them or below them.

“We worked with kids, teens, adults, and older folks,” Loebach says. “The event was fun because we got to work with so many different people.”

Providing hands-on lessons in the science of sound

On a Saturday in January, an event called The Science of Sound was held at the Bell Museum in St. Paul. Participants engaged in various scientific demonstrations about the physics of sound, the biology of hearing, and the history of audio recording. Faculty from St. Olaf College, including Norman Lee, Jeremy Loebach, and Eric Hazlett, provided interactive and educational activities. Lee's demonstration, 'Ear of the Beholder,' involved an app to explore how different animals perceive sound. Hazlett's demonstrations focused on the physics behind sound waves, while Loebach's focused on how the brain determines the location of a noise.