[daniellarusso]

They actually sell these devices, but they are IR motion activated, not via sound.

https://store.petsafe.net/ssscat-spray-pet-deterrent

[Nursie]

We have one of those, they're good but the refills are strangely expensive.

Turns out they fit some standard brands of canned air, I picked up some branded "ecomoist air duster" and it works really well, although slightly quieter, it still seems to work on our kitty.