U.S. Department of Transportation printed on recycled paper

National Highway Traffic Safety Administration

TRAFFIC TECH

Technology Transfer Series

Number 127 June 1996

DO MOTORCYCLE HELMETS INTERFERE WITH

THE VISION AND HEARING OF RIDERS?

Motorcycle crash statistics show that helmets are about minimum sound level (auditory threshold) was recorded

29 percent effective in preventing crash fatalities. That for each rider. Half of the riders were in the vision test

is, on average, riders wearing a helmet have a 29 percent and half in the hearing test condition.

better chance of surviving a crash than riders without a

helmet.

Opponents of mandatory state motorcycle helmet laws, The vision test showed that most riders recover the

however, have suggested that although effective in lateral field of view that is lost by wearing a helmet by

reducing injuries, helmets may increase a rider's risk of turning their heads a little farther. Before changing

crashing by interfering with the ability to see and hear lanes, 19 of the 23 riders compensated for the loss by

surrounding traffic. turning their heads more when they were wearing a

The National Highway Traffic Safety Administration riders did not require significantly more time to turn

(NHTSA) sponsored a study to assess the effect of their heads to check for traffic. Only four riders did not

wearing a helmet upon the ability of motorcycle riders compensate.

(1) to visually detect the presence of vehicles in adjacent

lanes before changing lanes, and Helmet use did not hamper the ability of riders to see

(2) to detect traffic sounds when operating at normal traffic or increase the time needed to visually check for

highway speeds. National Public Services Research nearby traffic. Overall, any negative interference of

Institute conducted the study for NHTSA. helmets on rider vision appears to be minor, especially

Fifty motorcyclists of various ages and riding should a crash occur.

experience participated in the study. The riders drove

their own motorcycles along a prescribed test route. 

The route was 5 and a half miles on a four lane divided

highway. In the vision test, the riders were asked to The hearing test showed that there were no significant

change lanes periodically, whenever they heard a signal differences in the riders' ability to hear the auditory

from a following vehicle. When they heard the signal, signals regardless of whether they were wearing a

riders were instructed to turn their heads to check traffic helmet or not. There was a difference, however, in the

in the adjacent lane, and then make the lane change in hearing threshold between travel speeds of 30 and 50

their normal manner. Each rider drove the test route mph. At the greater speed, all riders needed a louder

three times; once each while wearing a full coverage auditory signal because of increased wind noise. For

helmet, a partial coverage helmet, and no helmet. The any given speed, helmets neither diminished nor

degree of head rotation riders made during the lane enhanced hearing.

changes was measured. 

To assess the effect of the different helmets upon restrict the ability to hear auditory signals or the 

hearing, the volume of the sound signal used to prompt

the lane change was systematically varied. The

Vision Results

helmet than when they were not wearing one. These

in comparison to the protection offered by helmets

Hearing Results

These results indicate that wearing helmets does not
likelihood of seeing a vehicle in an adjacent lane prior

changing lanes. The information in this study will

benefit motorcycle safety advocates across the nation

seeking information about the impact of helmet usage

on motorcyclists' vision and hearing.

HOW TO ORDER

For a copy of The Effects of Motorcycle Helmets on

Seeing and Hearing (16 pages) write to the Safety

Countermeasures Division, NHTSA, 

NTS-23, 400 Seventh Street, S.W., Washington, DC

20590, or send a fax to (202) 366-7149.

U.S. Department 

of Transportation

National Highway 

Traffic Safety 

Administration

400 Seventh Street, S.W. NTS-33

Washington, DC 20590

TRAFFIC TECH is a publication to disseminate 

information about traffic safety programs, 

including evaluations, innovative programs, 

and new publications. Feel free to copy it as you wish. 

If you would like to receive a copy contact:

Linda Cosgrove, Ph.D., Editor, Evaluation Staff

Traffic Safety Programs

(202) 366-2759, fax (202) 366-7096

E-MAIL: lcosgrove@nhtsa.dot.gov