Not surprising, but still troubling: A new study from the University of Washington and Columbia University Mailman School of Public Health shows that subways are the loudest forms of mass transit in the city. Some of the noise levels recorded in the subway exceeded 100 decibels, which is loud enough to cause permanent hearing loss for regular straphangers if they're exposed to it for even as little as two minutes a day. (The subway system's average decibel level was 80.4) Health expert Robyn Gershon tells NY1, "For a typical day, you should not exceed between 70 and 75 decibels across that 24 hours. Once you do, it accumulates time after time, year after year, and after a while, you will have hearing loss." The MTA says noise reduction has long been a concern, and their efforts to hush up include retro-fitting stations with noise absorbing barriers and quieting track noise with welded rail fasteners. But we'd be happy if they could just do something about the maddening train brake screeching at Union Square!