Zeus CAN hear!!

At least he can hear some things!! We've had Zeus since April of 2009 and we were told by the breeder that he's deaf... completely deaf. Before I decided to get Zeus, I did on-line research about owning deaf dogs and what to expect. I read that although they're deaf, they may react to certain sounds that cause vibration... Since having Zeus, I find myself being much more aware of what noises make vibration. The lower the pitch, the stronger the vibration... However, some of the noises that Zeus reacts to are actually higher pitches. MUCH higher. I remember the first time Zeus 'heard' sound; one night I was putting away dishes and a couple of pans clanked together... HE FREAKED OUT!! Barking over and over and looking around with a startled looked on his face. I thought maybe that was a vibration thing... but since then he's had the same reaction over different things. He's been startled from the snapping noise when we put his collar on him, the clicking noise our computer chair makes when we get out of it and some other random sounds caused by daily living. I have a friend who is deaf but she can hear with hearing aides. I told her about this and she said that without her hearing aides on, SHE can hear certain pitches and not others, also!
Since we can't always control the pitches of sounds in our house, I'm not sure if this is a good thing or a bad thing for Zeus. I DO know it's gotta be confusing as heck for him! Imagine your day being spent without hearing sounds... and then out of the blue you hear something that you have no idea what it is or where it came from. It must scare him every time it happens... which is why he reacts with barking and fear in his eyes. It makes me sad :(