Are you sure this is the Index itself?
The Lighthouses have a high pitch noise. Also there is the famous coil whining that a lot of graphics cards do nowadays.
EDIT: Also the noise starting and stopping happens with the coil whining on my Nvidia GTX 1080 as well.
yes, I am. It's far too loud to be coil whine from the GPU, my 5700 XT doesn't really have any and that would also be far too silent in comparison to the base stations. The sound I hear is in a far higher pitch than what the lighthouses make (they have more of a buzzing than a singular frequency anyways) and it comes directly from the loud speakers of the Index - if I angle the speakers up or take the headset off then it's gone.
I tested some more and have found out some more info:
I've had this issue for a while as well in VRChat-- I find that moving the cursor over the quick menu buttons to make the little "boop" sounds will often make it go away.
Nothing extracted yet.
Describe the bug
When the sound on the Index is silent there's quite often a high pitched noise. It's not buzzing, seems to be one single frequency. That frequency also isn't always the same. Sometimes the noise starts and stops again several times a second (in regular intervals), sometimes it's continous.
To Reproduce
open the dashboard and click around a bit, between settings and the store for example. It will eventually start making the noise. This is not only happening in the dashboard but it seems like a reliable way to reproduce.
Expected behavior
In silence the loud speakers on the Index should stay, well, silent.
System Information (please complete the following information):
Note: Commenters who are also experiencing this issue are encouraged to include the "System Information" section in their replies.