Sounds - Which Ones Does Your Pig Recognize?

I'm not talking about the sounds that your pig makes, but the sounds that you make on a daily basis that they seem to respond to. We all know that they know the sound of a bag of chips, or food in their bowl, but what about other sounds that we make in our daily routine.

It was several years ago when living in NV that I noticed Chelie's reaction when I put on my winter coat. She had figured out the sound that it made when I put it on and knew that we were going outside. 

Lately I've been watching Porky and some of the other pigs to see which sounds they recognize. They seem to know the sound of the screen door opening, but only react when it is close to feeding time.
They do always seem to know when it's feeding time don't they?  Porky along with Rudy and Gracie seem to recognize the sound of the backdoor now and get all excited hoping that I will come over and let them out.

Most recently Porky has come to recognize the sound of the garage door going up/down. This isn't so bad most times when I'm leaving as he is usually still in his pen or far enough out in the yard, but I find myself racing to get the car into the garage and door closed before Porky when he is anywhere close by. You see he knows that is where the food is kept.

Porky guarding the garage.

Does anyone else have a similar experience?