Safer visual and auditory cues for elderly drivers is research goal


Blacksburg, Va. -- Toyota Motor Corp. is funding research at Virginia Tech aimed at better understanding the visual and auditory needs of the growing population of elderly drivers in the United States.

The project's principal investigator, Thurmon Lockhart of Blacksburg, assistant professor of industrial and systems engineering (ISE) and director of the Locomotion Research Laboratory at Virginia Tech, said the study will investigate visual changes that affect the way people of different ages view control panels in automobiles, as well as changes in the way drivers hear vehicle warning signals.

As we age, Lockhart noted, our visual acuity--the ability to see details at given distances--declines. This condition, called "presbyopia," makes it increasingly difficult for people over the age of 65 to focus on nearby objects. As it progresses, presbyopia can pose real safety problems for elderly drivers who find it difficult to read dashboard control panels and instrumentation.

Lockhart will study age-related visual acuity in both daytime and nighttime driving conditions using two test groups, one composed of 28 Virginia Tech students and the other of 28 people aged 65 and older. In addition to investigating how well drivers can see dashboard panels, Lockhart will study other factors including the effects of sunlight and nighttime glare, side window and rear window glare, and the effects of various types of windshield filters and internal and external mirrors.

The auditory displays research is being conducted in Virginia Tech's Auditory Systems Laboratory, directed by ISE Grado Professor John Casali and research associate professor Gary Robinson. These researchers are working with Lockhart to conduct auditory experiments with the two test groups.

As is the case with visual acuity, it is a consequence of the natural aging process for human hearing to become less sensitive, particularly at high frequencies. This condition is called "presbycusis," Casali explained. When presbycusis is combined with other forms of hearing loss, such as that due to noise exposure, the person is particularly compromised when trying to hear warning or other signals above about 2,000 cycles per second, or Hertz.

Drivers suffering from presbycusis can find it difficult to detect and interpret auditory warning signals, such as the mid-to-high frequency sounds that signal a truck backing up or the approach of emergency vehicles. In addition to simply detecting warning signals, drivers need to be able to tell the difference between a signal that indicates simple status information, such as low fuel, and those that are intended to convey "warning/caution" or "urgent/critical," the researchers said.

The Virginia Tech researchers will examine the relationship between the auditory qualities of warning signals and drivers' ability to interpret the sounds, as well as the variations in signal perceptions between young and elderly drivers. Toyota and other automotive companies are interested in developing on-board warning signals that will enhance safety for drivers of all ages, Lockhart said.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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