Crossword Dictionary
audio
audio, sound - n
the audible part of a transmitted signal; "they always raise the audio for commercials"
Audio means sound. If you turn up the volume and turn down the bass on your TV, you adjust the audio.
The noun audio always refers to what you can hear, although there are several different ways to use it. If you covet expensive speakers for your stereo, you wish for new audio equipment, and when someone complains about the sound at a movie theater he might say, "The audio is way too loud." Audio was first used as a prefix, in words like audio-frequency, and came to mean "recorded sound" in the 1930s.
etymology
"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").