Call static sound effect

[MorpheusXAUT]

With older (often analog) phone lines, low static background noise ("Hintergrundrauschen") could sometimes be heard. We could add this as an opt-in client side effect replicating older VCS systems whilst simultaneously serving as an indicator of a call successfully being established.
We should add this as another audio source applied on top of the rest of our audio stack. User can then toggle this effect on their side (default off).

[a3li]

I would also appreciate a mode where I get start and end of call signalled with a beep, separately/in addition to static background noise. Too many times I was too quick with the "go ahead" after accepting a call :D

[MorpheusXAUT]

I would also appreciate a mode where I get start and end of call signalled with a beep, separately/in addition to static background noise. Too many times I was too quick with the "go ahead" after accepting a call :D

Definitely on my TODO list, as I've run into that too many times myself as well 😅
I'll make it a separate issue 👍

EDIT: #322