Theory about my weird reaction to ice cracking

A few people know that the sound of ice cracking is like fingers on a chalkboard to me.

It's so bad that it feels like I get paralyzed and even after the sound is gone, it takes a few seconds for me to get over it, then I shudder.

Last night, my hubby offered me an ice lollie. He had to cut through some of it to get it open and the ice cracked... After we discussed it and came up with a few theories...

Theory 1.
Every person's ears are sensitive to a different frequency, that is why some people hate chalkboards, others teeth scraping on forks or loud chewing...

Theory 2.
The sound that bothers you the most is the sound/vibration your teeth make.

Theory 3.
Since my sensitivity to the sound of ice cracking only happened after I had my wisdom teeth removed, perhaps it is some form of PTSD. The sound of ice cracking could be similar to the sound my teeth made when the were pulled...

The last theory doesn't exactly explain why people hate fingernails on a chalkboard but it does explain why I always avoid cracking ice.