After noise of display very loudly regret backing driver (9)
I believe the answer is:
chauffeur
'driver' is the definition.
(I know that chauffeur is a type of driver)
'after noise of display very loudly regret backing' is the wordplay.
'after' says to put letters next to each other.
'noise of display' becomes 'chau' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'very loudly' becomes 'ff' (short for fortissimo, 'very loud' in music).
'regret' becomes 'rue' (to rue something is to regret it).
'backing' says the letters should be written in reverse.
'rue' reversed gives 'eur'.
'chau' put next to 'ff' is 'chauff'.
'chauff'+'eur'='CHAUFFEUR'
Can you help me to learn more?
(Other definitions for chauffeur that I've seen before include "Person employed to drive a car" , "One is paid to drive a car" , "One employed to drive a car for someone" , "Personal driver" , "Professional driver" .)