This is the 7085th most frequent Dutch word.
audio
Sound, especially as recorded, transmitted, or reproduced.
In this sentence, 'audio' refers to the sound quality of a specific recording.
De audio van de opname klinkt helder.
The audio of the recording sounds clear.
Here, 'audio' is used to describe the separate sound file or track associated with a documentary.
Ik heb de audio van de documentaire gedownload.
I downloaded the audio of the documentary.
In this usage, 'audio' is part of a term ('audio-engineering') that relates to a field of study dealing with sound technologies.