Put up sound beams (4)
I believe the answer is:
rays
'beams' is the definition.
(rays of light)
'put up sound' is the wordplay.
'put up' becomes 'raise' (synonyms).
'sound' indicates a 'sounds like' (homophone) clue.
'raise' is a homophone of 'RAYS'.
(Other definitions for rays that I've seen before include "Narrow beams of light" , "Beams from sun or moon" , "Sunbeams" , "Fish with wing-shaped fins and long tails" , "Columns of light or heat" .)