Do Cats Like Guitar?

I usually close the doors when I am practising because my wife seems to be - hm, let's say bored when I am playing the same piece on and on... and because I have three cats living in my house I used to think that it would be better to keep their sensitive ears away from heavy noise...
So I shut the doors, cranked up the volume and made my guitar scream. After about half an hour I decided to take a break - and was really shocked when I realised that my little cat was sitting on my bookshelf during the whole session! It made me feel so bad... I still wonder if this could have caused some damage to her ears? Ond the other hand she didn't seem to try to leave the room - maybe she even enjoyed it? Did I finally made it to get my first groupie?