I’ve got the same set up.
I think that has something to do with the date and time updates but I’m not sure.
The blinking lights will tell you if something is being sent when it isn’t you sending it.
Now that I think about it, I have heard people, always men talking. I never even thought about it being associated with the computer.
I would just dismiss it as maybe repairmen working around the general area and the wind or something picking it up. I actually have been sitting on my porch and heard men working several hundred yards away. They were installing a new warning light at the intersection. Some odd acoustics but now that I think about it, I can’t ever hear noises outside unless they are real loud as my house is very well insulated.