Endless examination of accounts show nothing is sound (5)
I believe the answer is:
audio
'is sound' is the definition.
(I've seen this before)
'endless examination of' is the wordplay.
'endless' means to remove the last letter.
'examination' becomes 'audit' (I've seen this before).
'of' becomes 'o''.
'audit' with its final letter removed is 'audi'.
'audi'+'o'='AUDIO'
'accounts show nothing' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for audio that I've seen before include "Acoustic reproduction" , "Sound recording" , "Denoting sound" , "Recording of acoustic signals" , "Prefix relating to sound" .)