Noise usually take the form of animals. They're not unlike Shadows, but frankly, they're cognitively even less.

[Shadows have some degree of substance behind them, some weight on the cognitive plane. Noise are just that.]

They're, effectively, the ground-up feelings and memories of the dead-and-less-than-dead that have yet to disperse. Static and ground pork of the soul. The seafoam that the mermaid turns into at the end of the tale.

If that seafoam was literally a pack of vicious wolves trying to rip your throat out, that is.

[And then Taboo Noise are worse because you can't even hurt them half the time! Everything was bad!]