<p>The distinctive roar of a Harley’s engine is loud, but studies have revealed the biggest source of noise for motorcyclists is actually generated by air whooshing over the riders’ helmets.<br /><br />Even at legal speeds, the sound can exceed safe levels. Now, they have identified a key source of the rushing din, the Journal of the Acoustical Society of America reports. Researchers placed motorcycle helmets atop mannequin heads, mounted them in a wind tunnel, and turned on the fans, according to a Bath statement.<br /><br />By placing microphones at different locations around the helmet and at the mannequin’s ear, they found that an area underneath the helmet and near the chin bar is a significant source of the noise that reaches riders’ sensitive eardrums.<br /><br />The team also investigated how helmet angle and wind speed affected the loudness. Future tests will move beyond the wind tunnel to real-life riders on the open road. The findings may one day be used to design quieter helmets, saving riders’ ears for the enjoyment of hard biker rock, the researchers said.<br /></p>
<p>The distinctive roar of a Harley’s engine is loud, but studies have revealed the biggest source of noise for motorcyclists is actually generated by air whooshing over the riders’ helmets.<br /><br />Even at legal speeds, the sound can exceed safe levels. Now, they have identified a key source of the rushing din, the Journal of the Acoustical Society of America reports. Researchers placed motorcycle helmets atop mannequin heads, mounted them in a wind tunnel, and turned on the fans, according to a Bath statement.<br /><br />By placing microphones at different locations around the helmet and at the mannequin’s ear, they found that an area underneath the helmet and near the chin bar is a significant source of the noise that reaches riders’ sensitive eardrums.<br /><br />The team also investigated how helmet angle and wind speed affected the loudness. Future tests will move beyond the wind tunnel to real-life riders on the open road. The findings may one day be used to design quieter helmets, saving riders’ ears for the enjoyment of hard biker rock, the researchers said.<br /></p>
