Seem a very quiet listener (6)
I believe the answer is:
appear
'seem' is the definition.
(synonyms)
'a very quiet listener' is the wordplay.
'very quiet' becomes 'pp' (musical abbreviation for pianissimo).
'listener' becomes 'ear' (body part which hears or listens).
'a'+'pp'+'ear'='APPEAR'
(Other definitions for appear that I've seen before include "Come into sight, materialise" , "Perform" , "Make an entrance as ghost may" , "Look - materialise" , "Develop" .)