Investigate loud noise of birds — Swedish, possibly (12)
I believe the answer is:
scandinavian
'swedish possibly' is the definition.
(Sweden is part of Scandinavia)
'investigate loud noise of birds' is the wordplay.
'investigate' becomes 'scan' (scan can mean to investigate or inspect).
'loud noise' becomes 'din' (din can mean a loud disturbance).
'of birds' becomes 'avian' (avian means relating to birds).
'scan'+'din'+'avian'='SCANDINAVIAN'
(Other definitions for scandinavian that I've seen before include "from part of Europe" , "Swede, perhaps" , "in northern Europe?" .)