"That assumes a lot of things: That they've detected us, that they have the ability to communicate over the distances (they might not have the technology and/or might not be sentient) and, finally, that they have any interest at all in contacting us."
I'm no expert, but I would also assume there's the chance that somebody IS trying to contact us, but in a way that we don't recognize as "communication."
Could be. After all, another species might view reality quite differently from us. They could be trying to communicate and wondering why we aren't picking up the phone.