Take public transit to work? Your hearing may be at risk, researchers say

Toronto — Brief episodes of intense noise exposure for city commuters – particularly those in and around public transit vehicles – could prove damaging in the long term, researchers from the University of Toronto warn in a new study.

Using a dosimeter microphone attached to a shirt collar about 2 inches away from an ear, researchers measured noise levels for different lengths of time on and around Toronto’s buses, subways and streetcars, as well as while walking, biking and driving.

On average, overall noise exposure was within acceptable levels, from 81.8 decibels for bike riders to 67.6 for drivers in a personal car. The peak noise level, however, went from 123.8 dB for bike riders to 108.6 for those in streetcars.

The peak level of noise for bus commuters exceeded 115 dB in 85 percent of the measurements. It was 20 percent for the streetcar commuters and 19.9 percent for people on the subway.

Over time, researchers said, those bursts of loud noise can add up.

“We now are starting to understand that chronic excessive noise exposure leads to significant systemic pathology, such as depression, anxiety, increased risk of chronic diseases and increased accident risk,” study author Dr. Vincent Lin, an otolaryngologist and associate professor at the University of Toronto, said in a press release. “Short, intense noise exposure has been demonstrated to be as injurious as longer, less-intense noise exposure.”

The Environmental Protection Agency states that exposure to 114 dB noises for more than four seconds can damage hearing.

“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,” Lin said in the release. “Planners need to be more considerate of noise exposure in future planning of public spaces and public transit routes.”

The study was published Nov. 23 in the Journal of Otolaryngology – Head & Neck Surgery.