[Canadauni]

This is an interesting theory. Probably one of the more plausible ones. I imagine some sort of biological or toxicological attack could cause some sound processing related symptoms.

On the wild end of things one could imagine it being a combination of sonic and chemical attack where the an innocuous chemical structure became active as a result of high frequency sound.

[emeraldd]

https://en.wikipedia.org/wiki/Sonochemistry I have no idea about that application, but the idea of using sound in chemistry seems to actually be a thing ...

[Canadauni]

At risk of oversimplification, sound is just energy and given the right amount of energy chemical changes can be carried out.