Investigator concerned with sound of spook (9)
I believe the answer is:
inspector
'investigator' is the definition.
(inspector is a kind of investigator)
'concerned with sound of spook' is the wordplay.
'concerned with' becomes 'in' (I've seen this in other clues).
'sound of spook' becomes 'spector' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in'+'spector'='INSPECTOR'
Can you help me to learn more?
(Other definitions for inspector that I've seen before include "Bus, train official" , "auditor" , "leading rank" , "Examining official" , "Police rank" .)
