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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Investigating the Safety of Commercial Motor Vehicle Operation by Deaf and Hard of Hearing Drivers

Project Goal:

The first objective of the project is to evaluate the safety of deaf and hard of hearing commercial motor vehicle (CMV) drivers by determining the crash rates of such drivers. The second objective is to identify and document procedures and recommendations that can be safely and effectively used with deaf and hard of hearing students during classroom, behind-the-wheel (training conducted in a parking lot or without traffic) and on-the-road (training conducted on a public road with traffic) commercial driver’s license (CDL) training and testing.


The hearing physical qualification standard for commercial drivers is found at 49 CFR 391.41(b)(11) of the Federal Motor Carrier Safety Regulations (FMCSRs). It states that a person is physically qualified to drive a CMV if that person first perceives a forced whispered voice in the better ear at not less than 5 feet, with or without the use of a hearing aid or, if tested by use of an audiometric device, does not have an average hearing loss in the better ear greater than 40 decibels at 500 Hz, 1,000 Hz, and 2,000 Hz, with or without a hearing aid, when the audiometric device is calibrated to American National Standard (formerly ASA Standard) Z24.5—1951.


The research team will conduct a literature review of scholarly sources. The literature review will focus on several research questions including:

•           What is the prevalence and incidence of hearing loss in the United States by age (e.g., individuals aged 18 or younger, 18 to 50, 50 to 60, 60 to 70, over 70)? How many individuals in the United States were born deaf or hard of hearing? What is the incidence of developing sudden deafness? Sudden deafness is an unexplained, rapid loss of hearing either all at once or over a few days.

•           How do individuals adapt to being deaf or hard of hearing, particularly with respect to behaviors relating to driving skills? How long does it take to develop adaptive skills?

•           How many deaf and hard of hearing drivers are there in the United States?

The research team will also summarize State driving regulations or criteria relating to deaf and hard of hearing drivers for intrastate CMV drivers, to include granting intrastate waivers or exemptions. The research team will also summarize international driving regulations or criteria for selected countries.  In addition, the research team will conduct interviews of  commercial driver training schools that provide training to deaf and hard of hearing students. The goal is to obtain their methodology for communicating with students during classroom, behind-the-wheel, and on-the-road training.