Do Motorcycle Helmets Interfere
With Vision and Hearing?
Opponents of motorcycle helmet wearing claim that full-face helmets interfere with vision and hearing. Poor vision or hearing from helmet wearing, they claim, can result in increased numbers of crashes and may even negate the protection provided by helmets in reducing head injury. The National Highway Traffic Safety Administration (NHTSA) in the United States sponsored a study in 1994 to examine the effect of helmets on vision and hearing (1).
Fifty motorcyclists drove their own motorcycles and wore their own helmets on a 5-mile road course. In the vision test, when they heard a signal from a following vehicle, riders were asked to turn their heads, check for traffic in the adjacent lane, and then make the lane change. The degree of head rotation riders made during the lane changes was measured. In the hearing test, the volume of the sound signal used to prompt the lane change was varied. The minimum sound – “auditory threshold” – for each rider was recorded. Twenty-five of the motorcycle riders were tested for lateral vision losses; twenty-five were tested for hearing losses.
Vision results
There is a loss of some lateral field vision when wearing a full-face helmet. Most riders, however, recover the slight loss of lateral field caused by wearing a helmet by turning their heads a little further to the left or right. Before changing lanes, 19 out of 23 riders compensated for the loss by turning their heads more when they were wearing a helmet as compared to when they were not wearing one. These riders did not require significantly more time to turn their heads to check for traffic.
This shows that helmet use did not hamper the ability of riders to see traffic or increase the time needed to visually check for nearby traffic.
Hearing results
There were no significant differences in the riders’ ability to hear the sound signals for changing lanes whether or not they were wearing a motorcycle helmet. There was, however, a difference in the hearing threshold between travel speeds of 30 and 50 miles per hour irrespective of helmet usage. At greater speeds, helmeted and unhelmeted riders needed a louder signal because of wind noise. At any given speed, however, helmets neither diminished nor enhanced hearing.
Wearing helmets does not restrict the ability to hear sound or the likelihood of seeing a vehicle in an adjacent lane prior to changing lanes.
Reference
(1) The Effects of Motorcycle Helmets on Seeing and Hearing is available from NHTSA. Write to Countermeasures Division, NHTSA, NTS-23, 400 Seventh Street, SW, Washington, DC 20590 USA. A summary of this report is available on NHTSA’s web site: www.nhtsa.dot.gov.
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