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Toronto study: bursty noise levels from public transport or biking could induce hearing loss

The noise levels to which commuters are exposed while using public transport or while biking could induce hearing loss if experienced repeatedly and over long periods of time, according to a study by researchers at the University of Toronto. Their open-access paper is published in the Journal of Otolaryngology - Head & Neck Surgery.

Efforts to control noise should focus on materials and equipment that provide a quieter environment, the researchers suggest. Hearing protection while using public transport should also be promoted.

This study is the first to look at and quantify the amount of noise people are exposed to during their daily commute, specifically on the Toronto Transit System. 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. Short, intense noise exposure has been demonstrated to be as injurious as longer, less intense noise exposure.

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. 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.

—Dr. Vincent Lin, corresponding author

Measuring noise exposure on public (subways, trams and buses) and private (cars, bike, walking) transport in Toronto, the researchers found that although noise on average was within the recommended levels of safe exposure, bursts of loud noise on both public and private modes of transportation could still place individuals at risk of noise-induced hearing loss.

According to thresholds recommended by the US Environmental Protection Agency (EPA), exposure to 114 A-weighted decibels (dBA) for longer than four seconds, exposure to 117 dBA for longer than two seconds and exposure to 120 dBA for longer than 20 seconds may put people at risk of noise-induced hearing loss.

A-weighted decibels express the relative loudness of sounds experienced by the human ear; taking into account that sensitivity to noise differs depending on noise frequency. Peak noise levels in dBa across both public and personal transport exceeded the EPA recommended thresholds. The average noise levels by bike were greater than any level caused by modes of public transit.

To measure noise exposure, the researchers used noise dosimeters, which they carried on their shirt collars about two inches away from their ears. The researchers collected 210 measurements in total, comparing the noise on subways, buses, and streetcars, while driving a car, cycling, and walking. They measured in-vehicle noise and outside or boarding platform noise for all modes of private and public transportation.

The authors found that 19.9% of the loudest noises (peak noise) measured on the subway were greater than 114 dBA, while 20% of the loudest noises inside streetcars were greater than 120 dBA. 85% of peak noise measurements from bus platforms were greater than 114 dBA, while 54% were greater than 120 dBA. All peak noise exposures while riding a bike exceeded 117 dBA, with 85% being greater than 120 dBA.

When the authors extrapolated the EPA recommended noise thresholds for an average Toronto commuter who uses public transport, the recommended level of noise exposure was exceeded in 9% of subway, 12% of bus, and 14% of biking measurements but not when using streetcars, cars or when walking.

The authors caution that the number of measurements taken for individual modes of transport is relatively low and that the cross-sectional nature of the study does not allow for conclusions about cause and effect. Further studies are needed to investigate other factors that may contribute to noise exposure such as use of music players and lengthy transit times.


  • Christopher M.K.L. Yao, Andrew K. Ma, Sharon L. Cushing and Vincent Y.W. Lin (2017) “Noise exposure while commuting in Toronto - a study of personal and public transportation in Toronto” Journal of Otolaryngology - Head & Neck Surgery 46:62 doi: 10.1186/s40463-017-0239-6



A good first step is for the police to enforce the vehicle noise laws and the courts to get serious and start fining abusers.

Brian P

I live here. Loudest noise on the subway is the horrendous screeching and clanging from the steel wheels whenever it goes around a bend inside the concrete tunnel, which contains and reflects all that noise. Streetcars produce the same noise, it's not contained and reflected back to its passengers but now everyone gets to hear it. Trucks, buses, construction activity, general traffic sounds contained and reflected within the concrete jungle add to the din. Vehicles with noisy exhausts are a small part of it (and have little or no influence on subway noise since the subways are separated from road traffic); typically in downtown Toronto, the only vehicles with engines running under heavy load when they make lots of noise are the underpowered buses and trucks.

Thomas Pedersen

I haven't been to Toronto but if it's anything like in the US, I'm not surprised by the conclusions of the study. When I first visited the US, I was appalled by the noise level everywhere.

From construction trucks sounding like they had no muffler, to clanging steel wheels (hint: air suspension works wonders with isolating the noise and not having the steel car work as a loudspeaker), to droning A/C's everywhere. The dishwasher sounded like it was tumbling the dishes, while the ones we bought in Europe at the time were marketed with noise level (around 45 dB at the time) as one of the main selling points.

The buses had extremely loud engines with a horrendous straining sound.

But I guess it was a little cheaper than getting noise down to a decent level...


I suppose people already do that with headphones - noise cancelling headphones ?
However, cyclists need to be able to hear what is going on around them, so they need "clear ears".
I am sure there is loads you could do once you brought in a few laws (as we have in Europe).

I was once in a factory in Germany where they had sound deadening material on the underneath of the tables and chairs in the canteen to keep the noise level down.
I suppose that was because the managers used the canteen as well as the workers.


Our subway cars run on tires and is relatively more quiet.

Diesel city buses are very noisy and each one pollute as many cars and are never checked by police and/or environment authorities. Nobody checks the noise and pollution from Harley-Davidsons, cars, SUVs, Pick-Ups, trucks, lawn machines etc.

It is a free for all?


As for the bus and the dishwasher...

Odds are the dishwasher was cheap. Our early 90s one was probably audible from the neighbors house. The new one, you can't hear it in the same room, for most of the cycle.

The trucks, most of the noise is probably coming from the radiator fan. It's like air cooled lawn equipment. So noisy. An electric fan would likely be quieter, but low speed diesels need a lot of cooling when they are working hard, so likely it was one with a viscous fluid fan clutch.

Harvey it comes down ability and training to enforce. What makes it too loud, what dbl etc. If it's not a set statute, than it can easily become a burden in court. Here, window glass tint is highly regulated, and there is a set percentage, but if a cop enforces it, he needs to use a tool to check it, and it has to be calibrated on that day, and he needs to be trained to use it, otherwise it could be argued in court wasting everyone's time and money. Where I live, only the state enforces it, highway troopers make tons of revenue pulling tinted cars over, local PDs don't see it as a protect and serve statue so to speak, so they are much less likely to enforce it as its more of a nuisance in the publics eye, and they are also less able to enforce it because of the tools, and that they have better things to do.


We switched from noisy NA made dish washers to BOSCH and Miele around 1995 and the noise problem was solved.

Noise meters are not very expensive and very easy to use. Were police force is not capable or willing, fixed and mobile fully automated stations (combined with radar speed stations) are not too costly and very effective.

The problem may be more political?

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