I also have the static noise in the speakers and it's so annoying when everything is quiet.
If you look at brighter scenes, the noise becomes more noticeable and you can't really ignore it.
It doesn't even matter if you disable the audio device or even unplug the USB cable, you can still hear it coming from the earphones.
Also, if you switch from 90Hz to 120Hz, the noise sounds a bit different (but never fixes it).
Honestly, if this can't be fixed I'd rather go back to the OG Vive with the Deluxe Audio and return this.