Sound Slow Effect

Hello there!
Im working on addon for workshop, and want to add slow motion sound effect in it, i don’t undestand how slow every sound that player recived.
Please help

It’s simple. That’s impossible.

[editline]9th December 2013[/editline]

[del]There’s is Entity:SetDSP(), it had something similar to slow mo, but you can’t control the slowmotion-ness of it.[/del] Nope, there’s only high-pitch one.

Oh this is im looking for.
You helpful as always, Thanks!