Needle in time removed from loudspeaker (5)
I believe the answer is:
annoy
'needle' is the definition.
(I know that needle is a more specific form of the action beset)
'time removed from loudspeaker' is the wordplay.
'time' becomes 't' (abbreviation).
'removed from' is a deletion indicator.
'loudspeaker' becomes 'tannoy' (tannoy is a kind of loudspeaker).
'tannoy' with 't' removed is 'ANNOY'.
'in' acts as a link.
(Other definitions for annoy that I've seen before include "Nark - nettle" , "Anger" , "Irritate - pester" , "Irritate, needle" , "get angry" .)