Harsh animal, we hear (6)
I believe the answer is:
hoarse
'harsh' is the definition.
(I've seen this before)
'animal we hear' is the wordplay.
'animal' becomes 'horse' (type of animal).
'we hear' indicates a 'sounds like' (homophone) clue.
'horse' is a homophone of 'HOARSE'.
(Other definitions for hoarse that I've seen before include "Croaky" , "A horse with croaking voice" , "Ashore (anag)" , "Of voice, rough and dry" , "Of voice, rasping or gruff" .)