Anxious listener starts to get emotional inside (5)
I believe the answer is:
eager
'anxious' is the definition.
(thesaurus)
'listener starts to get emotional inside' is the wordplay.
'listener' becomes 'ear' (I've seen this before).
'starts to' says to take the initial letters.
'inside' indicates putting letters inside.
The first letters of 'get emotional' is 'ge'.
'ear' going around 'ge' is 'EAGER'.
(Other definitions for eager that I've seen before include "really keen" , "Keenly expectant" , "Agree (anag.)" , "Keen - enthusiastic" , "Sharp" .)