Heighten the beams, one hears (5)
I believe the answer is:
raise
'heighten' is the definition.
(I know that heighten is a more specific form of the action raise)
'beams one hears' is the wordplay.
'beams' becomes 'rays' (rays of light).
'one hears' indicates a 'sounds like' (homophone) clue (I've seen 'heard of' mean this).
'rays' sounds like 'RAISE'.
'the' acts as a link.
(Other definitions for raise that I've seen before include "Increased earnings in America" , "Contact" , "Lift up or rear" , "Hoist" , "Gather" .)