Certain sounds effects are audible even when muted

One of Delirium effects can still be heard. I don't know what it's called, looks like some ground rune and explodes like a mortar; taken from Simulacrum fight, but it's same in maps too.

Another one is the sound effect from the Legion encounter and belongs to one of the monsters, but I can't capture it. It sounds like fireworks.

Those can be heard despite my Music, Sound Effects and Ambient Sound turned off. I even checked in my config file to make sure they aren't sitting at very low volume. They all are indeed at 0.
My audio settings: