This is because, according to their “Aeroacoustic Sources of Motorcycle Helmet Noise” study, the biggest source of noise for motorcyclists is not the roar of a motorcycle’s engine, but rather the noise generated by air passing over their helmets.
Even when riding at legal speeds, bikers may be exposed to unsafe noise levels, they say.
In performing the study, the British scientists placed motorcycle helmets on mannequin heads, mounted them in a wind tunnel and turned on the fans, recreating the wind and noise situation from the riding experience.
By placing microphones at various locations, the researchers found that an area underneath the helmet and near the chin bar is a significant source of the noise that reaches a rider’s eardrums. The team also investigated how helmet angle and wind speed affected the loudness.
“Intuitively it is clear that wearing a motorcycle helmet will change the way in which people perceive sounds,” the researchers not. “There are both engineering and psychology aspects to understanding this process.”
However, the researchers reinforce the idea that riders who wear helmets reduce their risk of skull fractures and fatal accidents.
As for the hearing loss issue, ear plugs are strongly recommended. Future tests will move beyond the wind tunnel to real-life riders on the open road.