Audio circuits fall into disuse (5)
I believe the answer is:
lapse
'fall into disuse' is the definition.
(I've seen this in another clue)
'audio circuits' is the wordplay.
I cannot really see how this works, but
'circuits' could be 'laps' ('lap' can be a synonym of 'circuit') and 'laps' is found within the answer.
A single letter 'e' remains which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for lapse that I've seen before include "Brief failure of judgement" , "Fall from grace" , "Careless mistake" , "Pass into disuse" , "Error; oversight" .)