the marching band was as loud as a train horn.
As loud as thunder. You could always think of something else really loud and put it in the place of thunder. Could be the motorway, a waterfall, or a train.
as loud as a dinosaur
It's a simile. It is also an oxymoron, with the idea of loud quiet (the noun quiet modified by the adjective loud).
a simile is a comparison to an object, ex: as agile as a cat as angry as a wasp as loud as an elephant he fights like a lion he runs like a cheetah flopping like a fish
As cute as a puppy as tall as a giant as big as a elephant as loud as a chimpanzee As stupid a bird's brain
as noisy as
A simile.
In the Odyssey, the blinding of the Cyclops Polyphemus is compared to when a blacksmith plunges a large axe or auger into cold water to cool it, causing a loud hissing sound and steam to rise. This simile emphasizes the violence and forcefulness of the act.
A metaphor
It is a simile.
As quick as a wink is a simile. ----