It's a simile. It is also an oxymoron, with the idea of loud quiet (the noun quiet modified by the adjective loud).
Often they are not. Many tornado produce a loud roar often said to be similar to that of a freight train.
Forte is loud. Rest & Piano is quiet in music
quiet for us.
loud
Quiet Is the New Loud was created on 2001-03-06.
Quiet Mouth Loud Hands was created in 2007.
it is loud
quiet.
loud
I have 5 pigs and they are only loud if they are about to eat or if you slap them in the butt so they are mostly quiet
loud
It can be loud or soft, depending on how it is played.