The U.S. Department of Transportation (DOT) Transportation Security Administration (TSA) provides information about airport security screening for air travelers at http://www.tsa.gov/travelers [1]. Specific information for travelers with disabilities, and for people who are deaf or hard of hearing, is available at http://www.tsa.gov/travelers/airtravel/specialneeds [2].
If you experience discrimination during the airport screening process, you can file a complaint [3] with the TSA.
Links:
[1] http://www.tsa.gov/travelers
[2] http://www.tsa.gov/travelers/airtravel/specialneeds
[3] http://www.tsa.gov/travelers/customer/discrimination.shtm