Earl hears about dramatic trial (9)
I believe the answer is:
rehearsal
'dramatic trial' is the definition.
'rehearsal' can be an answer for 'trial' (I've seen this in another clue). I am not certain of the 'dramatic' bit.
'earl hears about' is the wordplay.
'about' indicates an anagram.
'earl'+'hears'='earlhears'
'earlhears' with letters rearranged gives 'REHEARSAL'.
Can you help me to learn more?
(Other definitions for rehearsal that I've seen before include "Practice session in preparation for public performance" , "Dry run" , "Play run-through" , "Practice - run-through" , "show trial" .)