Strange happenings after cat walked on keyboard

While I was using my iMac, my cat walked across my keyboard apparently pressing different key combinations. I now notice two obvious differences that I can't figure out how to change. The function keys across the top of the keyboard are not working and a dark black box appears around what I'm using or highlighting. Presently, I have none of the normal sounds (beeps, etc.) If I go to preferences to try to turn sound on, I get the "robot voice" which I don't like. I'm baffled and frustrated. Any ideas about how I can correct this? I hoped it would be "cured" after shutting down overnight. No such luck!