From WordNet (r) 3.0 (2006) [wn]:
audio
n 1: the audible part of a transmitted signal; "they always
raise the audio for commercials" [syn: audio, sound]
2: an audible acoustic wave frequency [syn: audio, {audio
frequency}]
3: a recording of acoustic signals [syn: sound recording,
audio recording, audio]
4: the sound elements of television
From The Collaborative International Dictionary of English v.0.48 [gcide]:
audio \audio\ n.
the part of a transmitted signal which conveys the sound of
the event represented by the signal, such as that of a
television program. "they always raise the audio for
commercials"
Syn: sound.
[WordNet 1.5]
2. 1 an audible acoustic wave frequency.
Syn: audio frequency
[WordNet 1.5]
3. the sound elements of television.
[WordNet 1.5]
From The Free On-line Dictionary of Computing (8 July 2008) [foldoc]:
audio
<file format> Sound, one component of multimedia. Computers
(and audio compact discs and digital audio tape) work with
digital audio, in contrast to vinyl disks or analogue tape.
(1999-07-30)