One of the many odd things about this event is that I don't recall anyone mentioning noise from the drone. An airport is a very noisy place air-side, but it might have been relatively quiet during the shutdown period.
I've had one drone encounter: A small one flew directly over my house and parked, maybe around 400 feet up. It was probably filming a town parade happening a block away in our neighborhood. Even with the noise of the marching bands warming up, I heard the drone before I saw it, and knew to look up in the sky.
These things are not quiet, especially any of the larger pro video or agricultural models. Even the smaller ones (like the one over my house) make enough noise to attract attention. But as far as I know, these "sightings" were all visual. Did anyone mention hearing anything?