热点大瓜

What are the loudest sounds at UB? 

Where are the university’s quietest spots? 

What unlikely noises here are around 60 decibels, the level typically associated with a normal conversation between two people?

Students recently traversed the North Campus to answer these questions, with physics. Equipped with sound level meters (i.e., their smartphones), they’ve measured and recorded sound levels in various campus locations, from the Student Union during peak hours to the most sparsely travelled basement hallways.

“The goal is to help students better understand the underlying principles of sound and show them that, even without a formal scientific background, they can scientifically investigate the world around them,” says Benedikt Harrer, associate teaching professor of physics, College of Arts and Sciences.

The assignment is part of the physics of music course. Offered since 2021 as part of the university’s first-year seminar program, this offering of PHY 199 aims to bring together two subjects often seen as disparate and explore the intersection of art and science. 

“Physics is not just purely abstract, mathematical thinking. A lot of it is very creative work, and in many regards is actually very similar to what musicians do,” Harrer says.

The goal of the assignment is to determine sound-intensity level, or the intensity of a sound wave as it moves through the air relative to the human threshold of hearing. It’s measured in decibels, with every 10-decibel increase representing a tenfold increase in sound intensity.

Sound intensity is about much more than loudness, which is our perception of sound. If you double the intensity of a sound wave, it doesn’t necessarily mean it will sound twice as loud. Typically, a 10-decibel increase in sound-intensity level is considered to correspond to a doubling in perceived loudness.

“Our perception of loudness depends on our own hearing abilities and is a subjective experience,” Harrer explains.  

In the assignment, students typically try to stand about three feet away from the sound source when measuring sound-intensity levels. A host of free-to-download apps can measure sound-intensity levels, providing them with an easy way to conduct their own research outside the classroom.

The assignment typically takes the form of a competition, where teams compete to find the loudest sound, the quietest sound and the most curious sound closest to 60 decibels, the level of most normal conversations.

Some of the loudest sounds tend to come from the more obvious places, such as the Student Union. However, a student once surprised the class by finding sounds around 90 decibels coming from vents at a loading dock behind the Natural Sciences Complex.

Last year, a student in the Thunder of the East measured the marching band’s practice. 

“They realized just how dangerous those kinds of sound levels can be if you’re not taking steps to protect your hearing,” Harrer notes.

Many of the quietest sounds, around 30 decibels, have come from campus wildlife, from a hawk chirping outside Governors Complex to a garter snake making its way through grass. Some of the more surprising sounds found to be at 60 decibels have included a vending machine and the ding of an elevator.

Students have also come back with some interesting observations of campus spaces, Harrer says. They’ve found some hallways and basements are quieter than the silent study spaces in the libraries. Empty bathrooms can be among the quietest places on campus, or among the loudest if the hand dryer is running.

One of their more recent findings is that the temporary Stampede buses being used this academic year are quieter than the previous buses. Whereas buses in the old fleet often could reach 100 decibels as they pulled away, the current fleet, a set of 4o-foot Gillig transit buses from new service provider WeDriveU, are closer to 80 decibels, Harrer says.

The new fleet coming to campus this fall may be even quieter, as the goal is for it to be 40% electric within two years.

“It was very interesting to see how the soundscape on campus has changed in the years we’ve been doing this assignment,” Harrer says.

Above all, the assignment gives first-year students a reason to explore campus. Harrer previously taught the physics of music course as an upper-level elective at San Jose State University, but upon arriving at UB in 2020, he retrofitted it to be part of the UB Seminar program, which introduces first-year students to life at UB.

“I thought you could embed lessons on how to be a successful college student into a context that hopefully is interesting to students,” he says. “And the sound assignment is really an excuse to get them to venture into parts of campus they maybe haven’t been before.”

The course explores intensity and other properties of sound, such as wavelength and frequency, before diving into the inner workings of musical instruments. Other assignments include listening to the same album on tape, vinyl and CD to spot the differences. Some students have even produced their own musical compositions and built their own instruments, from a recorder made of paper to a ukulele built in a woodshop.

Harrer was an active musician growing up in his native Germany, playing the trumpet, violin, piano, drums and “a lot of Bavarian folk music,” but no longer had the time once he started graduate school.

The course allows him to explore his passion for music, at least twice a week. He hopes it does the same for students with similar varied academic interests.

“There may be science majors who are curious about the humanities, but wouldn’t necessarily take a music class, or humanities majors who are curious about science but wouldn’t necessarily take a physics class,” he says.