Observes sounds (5)
I believe the answer is:
notes
This clue is a double definition.
'observes' is the first definition.
('note' can be a synonym of 'observe')
'sounds' is the second definition.
(I've seen this before)
(Other definitions for notes that I've seen before include "Memos; marks" , "Marks on a stave" , "Written comments" , "Sees" , "Takes into account" .)