Note about what listeners practise (8)
I believe the answer is:
rehearse
'practise' is the definition.
(synonyms)
'note about what listeners' is the wordplay.
'note' becomes 're' (as in do-re-mi).
'about' is an insertion indicator.
'what' becomes 'eh' (sound used to ask 'what?' or 'pardon?').
'listeners' becomes 'ears' (body parts which listen).
'eh'+'ears'='ehears'
're' enclosing 'ehears' is 'REHEARSE'.
(Other definitions for rehearse that I've seen before include "Practice in theatre" , "Practise like actor" , "Practise before a public performance" , "Train" , "Cast practise for play" .)