They're known to be loud speakers, possibly in court (7)
I believe the answer is:
actions
'they're known to be loud speakers possibly' is the definition.
The definition suggests an adverb but the answer is not.
'court' is the wordplay.
I cannot really see how this works, but
'court' could be 'ct' (abbreviation used in road names) and 'ct' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'in' is the link.
Can you help me to learn more?
(Other definitions for actions that I've seen before include "It's said they speak lounder than words" , "Cases" , "Deeds" , "Gestures" , "Things done (instead of said)" .)