Can riding the subway every day damage your hearing?

Each weekday, over five million people descend into the New York City Subway system, and ride through the bowels of the New York area.

Everyone seems to have their own strategy while waiting for the train to come.  There are the readers, the sitters, the talkers, the ones who constantly crane their necks hoping to be the first to spot the train.  But few people are plugging their ears, and we all probably should be.

Studies show that at its noisiest – when the train is coming into the station – subway platforms can reach up to 106 decibels.  It only takes thirty seconds of exposure to sounds that loud before noise-induced hearing loss can occur, according to both the World Health Organization and Environmental Protection Agency.  And once the cells in our ears – called hair cells – are damaged, they cannot grow back.

On average, however, stations are around 80 decibels, which can cause hearing loss after 160 minutes of exposure.  (Hint: If you’ve been waiting that long for the train, it’s probably not coming).

Decibels, the most common unit of sound volume, increase logarithmically.  So a ten-fold increase in the decibel value means a hundred-fold increase in the intensity of the noise. Moderate rain, for example, is about 50 decibels.  That means that the loudest subway station measured (106 decibels) is about 100,000 times louder* than the sound of rain.

What this means for subway noise is that very small increases in decibel level can mean very big problems for your ears.  The average subway station may be ok for 160 minutes, but just a few more decibels and the amount of time you’ve got before it can really damage your hearing drops off quickly.  At 85 decibels you’re safe for 54 minutes.  At 90 you have 27 minutes, and at 106 decibels you only get thirty seconds before the sound can cause damage to the delicate parts of your inner ear.

And once you get on the train, your hearing is still not necessarily safe.  Inside the subway car can be just as loud as the platform.  Add your mp3 player, which you have to turn up to hear above the noise (by the way, the rest of us can hear it too), and your ears are in for a rough ride.

If all this has you considering switching to buses, think again.  Bus stops can be almost as loud as platforms – and buses themselves are a source of all sorts of beeping, hissing and rumbling that can damage your hearing.

Noise-induced hearing loss effects as many as 10 million people in the United States.  (Maybe that’s why New Yorkers are shouting at each other all the time?)  Public health officials say that governments should spend money to improve and quiet down their equipment.  In the meantime, many experts recommend using earplugs when traveling on the subway.  It might look dorky, but it could save your hearing.

* You may have noted that earlier versions of this blog had this number at 500.  Thanks to Kevin Wiley for pointing out the error in my math.