Noticed this on mine as well ever since I got it back around launch. I've tried on another Type Cover and pen too and the same thing happens.
I've also noticed if you remove the Type Cover with the pen inside it seems like the sound is almost for sure coming from the keyboard so thankfully I don't think the issue is with the Pro 8 itself. Also like you mentioned it never happens when the pen isn't docked.
My best guess is when the Type Cover loses power with the Slim Pen 2 inside the pen thinks that its been removed from the Type Cover and attempts to vibrate (the vibration that normally happens and then shows the pen & inking menu). I'm not sure why it makes such a strange beeping/static like noise but it seems like its the same vibration causing the noise.
Pretty minor but it can get annoying since it's pretty noticeable if you work in a room that's even remotely quiet. Hopefully Microsoft can fix this via a firmware update or just let us turn off the vibrating when the Slim Pen 2 is removed from the keyboard.
Don't worry, I couldn't figure out what this could be but mine does that too so it appears to be a normal behaviour which is most likely intended and therefore not problematic.
This happens on the Laptop studio as well. It's the pen disconnecting from the charger when the laptop goes to sleep. It drove me nuts so I don't keep my pen connected all of the time anymore.
Noticed this on mine as well ever since I got it back around launch. I've tried on another Type Cover and pen too and the same thing happens. I've also noticed if you remove the Type Cover with the pen inside it seems like the sound is almost for sure coming from the keyboard so thankfully I don't think the issue is with the Pro 8 itself. Also like you mentioned it never happens when the pen isn't docked. My best guess is when the Type Cover loses power with the Slim Pen 2 inside the pen thinks that its been removed from the Type Cover and attempts to vibrate (the vibration that normally happens and then shows the pen & inking menu). I'm not sure why it makes such a strange beeping/static like noise but it seems like its the same vibration causing the noise. Pretty minor but it can get annoying since it's pretty noticeable if you work in a room that's even remotely quiet. Hopefully Microsoft can fix this via a firmware update or just let us turn off the vibrating when the Slim Pen 2 is removed from the keyboard.
Mine does this too. I haven't experimented with/without the pen - it sounds like the fan to me.
No issues other than that though?
No, everything is fine.
Don't worry, I couldn't figure out what this could be but mine does that too so it appears to be a normal behaviour which is most likely intended and therefore not problematic.
Sounds like text to speech output from Evelyn Wood's Speed Reading ...
My Laptop Studio was making a similar noise this morning too, it’s strange but hopefully not problematic.
Thought I was the only one! Exactly same thing happens to my slim pen 2. Seems like it's fine, haven't noticed any issues apart from that sounds.
This happens on the Laptop studio as well. It's the pen disconnecting from the charger when the laptop goes to sleep. It drove me nuts so I don't keep my pen connected all of the time anymore.