You might want to don some earmuffs next time you take the train. The University of Toronto conducted research into commuter sound levels, and discovered a cacophony of noises that could induce hearing loss. The findings, published on Wednesday, suggest more should be done to ensure quieter trips.

“We were surprised at the overall average noise exposure commuters experience on a daily basis, especially the peak noise intensity not only on trains but also on buses,” says Vincent Lin, author of the study. “Planners need to be more considerate of noise exposure in future planning of public spaces and public transit routes. Toronto in particular, as the transit network expands, needs to consider ways to reduce noise exposure as a preventative measure for future health risks.”

The study has been published in the Journal of Otolaryngology - Head & Neck Surgery.

The team collected audio samples from subways, trams and buses, as well as private modes of transport like cars, bikes and walking. They placed noise dosimeters on their shirt collars, two inches away from their ears. In total, the group collected 210 measurements, and found something shocking.

The Environmental Protection Agency claims that exposure to 114 A-weighted decibels (a special measure aimed at measuring noise frequency as it is experienced in the ear) for more than four seconds could cause hearing loss. On the subway, 19.9 percent of the loudest noises were above 114 dBA, while in a car, around a fifth of noises reached 120 dBA. All of the loudest noises experienced by a bike went past 117dBA, while 85 percent were as loud as 120dBA.

Cycling can lead to high levels of noise.
Cycling can lead to high levels of noise.

When the agency’s exposure guidelines were taken into consideration, the team found that noise reached unsafe levels nine percent of the time on the subway, 12 percent on the bus and 14 percent when cycling. However, noise remained within safe limits in streetcars, cars or walking.

The study does note, however, that more research needs to be done on whether these patterns hold true in all situations. It also fails to take into account longer transit times, which could vary the amount of exposure.

The amount of exposure is also likely to change as new modes of transport develop. Electric cars, set to enter the lives of more people as time progresses, are also likely to cut back on noise thanks to their silent motors over traditional gas engines. Virgin Hyperloop One, which is currently developing a vacuum-sealed pod system that would transport people at up to 700 miles per hour, is also confident that its system would run nice and quietly:

Based on the physics of the system — non-contact motion through a steel tube — we anticipate the noise you’d hear from the outside the tube as the pod goes by at more than 500 mph would be equivalent to the sound of a truck with no wheels and no engine going 65 mph down a freeway. In other words, just a big whoosh.

For the sake of our eardrums, let’s hope the inside of the finished pod is just as quiet.


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