I figured-out that the throbbing bass sound is coming from the return air grill on an air conditioner. It is weird because it is not noticeable except in the same corner and the opposite corner of the room. In between the two corners, I can't hear the throbbing.

I could hear the birds chirping - even with my ears plugged, so I guess that would be hallucination. It's like my brain was so used to hearing the birds chirping from the first location I was sleeping, that I continued to hear birds chirping in my head after relocating away from the birds.

I also have a problem with fragrances and perfumes. I seem to be hyper-sensitized and easily upset by things that I never would have noticed until this past year.

Anyway, it's minor stuff as long as it isn't the prelude to another psychotic episode. Thanks for the help, everybody.