The “Aeroacoustic Sources of Motorcycle Helmet Noise” study, which was published in the Journal of the Acoustical Society of America, found that the noise inside of your helmet can reach dangerous levels, even while driving at legal speeds. Researchers from the University of Bath placed helmets on mannequins and placed them in a wind tunnel. The researchers measured the noise of the wind at different points in and around the helmet. “Intuitively it is clear that wearing a motorcycle helmet will change the way in which people perceive sounds,” the study reads. “There are both engineering and psychology aspects to understanding this process.”
The researchers found that the opening at the chin of a full-face helmet was the main source of noise. The researchers also looked at how speed, helmet angle, and venting affected the noise level. The study could help improve helmets so that motorcyclists can ride safely without worrying about the constant din of the wind. But for the time being, you should probably just wear ear plugs.