"sound," especially recorded or transmitted sound signals, 1934, abstracted from word-forming element audio- (q.v.), which is from Latin audire "to hear" (from PIE root *au- "to perceive").
Entries linking to audio
audio-
word-forming element meaning "sound, hearing," from combining form of Latin audire "to hear" (from PIE root *au- "to perceive"); used in English word formation by 1890s.
*au-
Proto-Indo-European root meaning "to perceive."
It forms all or part of: aesthete; aesthetic; anesthesia; audible; audience; audio; audio-; audit; audition; auditor; auditorium; auditory; hyperaesthesia; kinesthetic; oyer; oyez; obedient; obey; paraesthesia; synaesthesia.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit avih, Avestan avish "openly, evidently;" Greek aisthanesthai "to feel;" Latin audire "to hear;" Old Church Slavonic javiti "to reveal."
video adj.
1935, as visual equivalent of audio, from Latin video "I see," first person singular present indicative of videre "to see" (see vision). As a noun, "that which is displayed on a (television) screen," 1937.
Engineers, however, remember the sad fate of television's first debut and are not willing to allow "video transmission" (as television is now called by moderns) to leave the laboratory until they are sure it will be accepted. [The Michigan Technic, November 1937]