Sounds produced by this cat round a queen (6)
I believe the answer is:
larynx
'sounds produced by this' is the definition.
(larynx means the voice box)
'cat round a queen' is the wordplay.
'cat' becomes 'lynx' (lynx is a kind of cat).
'round' means one lot of letters goes inside another.
'queen' becomes 'r' (abbreviation for regina, e.g. in ER ).
'a'+'r'='ar'
'lynx' placed around 'ar' is 'LARYNX'.
(Other definitions for larynx that I've seen before include "Organ containing the vocal cords" , "part of throat with vocal chords" , "Where growls come from" , "Cavity containing vocal chords" , "part of pipe" .)