Muffled sounds using soundscapes?

Is there a way to use soundscapes in a way that you can modify the pitch/clearness of in-game sounds?

For example, change the audio like when you fall into water, but using a soundscape instead.
I haven't found information about it and I'm an entry-level soundscape user.

Maybe another entity can do this?

Thx

MQ

Thanks Tony!
I made my own soundscape and .mp3 file. It works in-game.

Problem is, any value I put for DSP in the txt file doesn't change sounds at all.

I tried 14, 26 and it really doesn't sound like water or weird, like it should. 4 and 5 don't change a thing either.

Any idea, possible bug?

EDIT: it does seem to work when using dsp_volume cranked at 10, but the effects are still so subtle.

MQ