My 2005 has a very similar noise from the round thingy over & to the left side of the drivers head. It kinda sounds like a small fan to me. But how do ya get access to that item? Is there some schematic for it?
I believe that pops out of the headliner if gently pried out. There are a couple of retention clips molded into the plastic holding in the headliner panel. The sensor should snap out of/into the the face plate.
I didn't watch, but here is a YouTube on it...
I have heard they can make that noise after sucking in dirt and dust over the years. I saw a post somewhere, where a can of compressed gas (a can of computer/electronics duster things) was used to blow some crud out to solve the issue.
Mine makes a slight buzz once in a while, but I have not found the urge to pay $50 for a new one. I live the the occasional noise.