Listen again to Sarah in practice (9)
I believe the answer is:
rehearsal
'practice' is the definition.
(rehearsal is a kind of practice)
'listen again to sarah in' is the wordplay.
'listen' becomes 'hear' (I've seen this before).
'again' becomes 're'.
'to sarah' becomes 'sal' (Sally is a common pet form of Sarah).
'in' indicates putting letters inside.
're'+'sal'='resal'
'hear' going within 'resal' is 'REHEARSAL'.
(Other definitions for rehearsal that I've seen before include "Play run-through" , "Practice in theatre etc" , "show trial" , "preparation in house?" , "Practice session in preparation for public performance" .)