Oh gosh this is me. I am very sensitive to sounds and if I am anxious or upset, I am hyper-sensitive. One example, I had a co-worker who had a squeaky "s" when she spoke meaning her "s" sound had a high pitched whistle in it. This drove me crazy. She didn't even sit close to me but if I could hear it at all, I would just become fixated on it. And yes, I did feel crazy because I would look around the room and wonder why I was the only person who was bothered by the squeaky "s". Thankfully that woman found another job and I got some relief. Oh but the guy who replaced her snaps his gum. Arrrgh.

I also have a very hard time having a conversation in a noisy restaurant or bar. I can't concentrate and I end up shutting down.

Sorry I can't answer your question about why this is. My father is also sensitive to sound. Maybe it's genetic?

If anyone has any suggestions about how to reduce this sensitivity I would like know. I was told that learning to meditate would be helpful so I attended a seminar on meditation techniques and had to spend an agonizing hour sitting next to a heavy breather trying to quiet my mind. Torture.