Sounded loud in Germany (8)
I believe the answer is:
fathomed
'sounded' is the definition.
('fathom' can be a synonym of 'sound')
'loud in germany' is the wordplay.
'loud' becomes 'f' (short for forte - 'loud' in music).
'in' becomes 'at home' (someone at home is 'in').
'germany' becomes 'd' (vehicle registration code for Deutschland).
'f'+'athome'+'d'='FATHOMED'
(Other definitions for fathomed that I've seen before include "Got" , "Sounded" , "Deeply understood" .)