Background and initial audience characteristics of the closed-caption television system.
D003143:Communication Devices for People with Disabilities / Q000706:statistics & numerical data*; D003638:Deafness / Q000534:rehabilitation*; D006801:Humans; D012656:Self-Help Devices / Q000706:statistics & numerical data*; D013690:Television / Q000706:statistics & numerical data*; D014481:United States