Gap in wood’s incomplete, by the sound of it (8)

I believe the answer is:
knothole
'gap' is the definition.
(knothole is a kind of gap)
'wood's incomplete by the sound of it' is the wordplay.
'wood's' becomes 'knot's' (knot is a kind of wood).
'incomplete' means to remove the last letter.
'by the sound of it' becomes 'hole' (I can't explain this - if you can you should believe this answer much more).
'knots' with its last letter taken off is 'knot'.
'knot'+'hole'='KNOTHOLE'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for knothole that I've seen before include "Flaw in deal" , "Flaw in a piece of prepared wood" , "Flaw in timber" , "Timber fault" , "Gap in wood" .)
