From Wiktionary, the free dictionary

close captioning (uncountable)

1. Alternative form of closed captioning.

   • 1992 March-April, Mental and Physical Disability Law Reporter‎^[1], volume 16, number 2:

     the prison did not have basic assistive devices, including a telecommunications device for the deaf (TDD), close captioning devices, and visual alarms and signals.

   • 2016 December, April Karen Baptiste, “Can a Research Film Be Considered a Stand-Alone Academic Publication? An Assessment of the Film ‘Climate Change, Voices of the Vulnerable: The Fishers’ Plight.’”, in Area 48‎^[2], number 4:

     Additionally, in a research-film, faces being blurred can ensure confidentiality, voices can be changed, and subtitles or close captioning can be used to disguise the identity of an informant who wants to be anonymous.

   • 2018, Bobbie Bushman, “Serving Underserved Populations: Implications from a Model of Successful Services for Deaf and Hard of Hearing Children in Public Libraries”, in The International Journal of Information, Diversity, & Inclusion‎^[3], volume 2, number 3:

     D/HoH people require close captioning and assistive technologies to access electronic and audio-visual information, including news and current events.

• “close captioning”, in OneLook Dictionary Search.