Conductor sent up, by the sound of it (5)
I believe the answer is:
guide
'conductor' is the definition.
(I've seen this before)
'sent up by the sound of it' is the wordplay.
'sent up' becomes 'guyed' (I've seen this before).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'guyed' is a homophone of 'GUIDE'.
(Other definitions for guide that I've seen before include "Direct; show the way to" , "Pilot" , "One who leads" , "Direct, influence" , "Steer" .)