Hi Trippin,
Actually a lot of what you said I can relate to.
Sensory overload: usually auditory for me but also visual if there are too many blinking lights. Auditory stimulation overload sends my irritation and aggrivated states rolling.
Mishearing: This happens to me all the time. Words just become mush as people speak them. It drives my husband crazy because I know I just stare at him blankly and go "what?"
Forgetting date/time of day: I'm always answering the work phone wrong. "Good morning" or "Good afternoon" are my biggest issues. People make fun of me for it.
Transposing numbers comes out of this, too. Stupid mistakes, like you said. I transpose 3 and 9, 2 and 7, and others randomly.

Sometimes it takes 3 tries to dial a phone number.
As for the sounds and numbers jumping out at you, etc. I would say that is some type of hallucination or something going on. Even if it isn't seeming like a huge deal, I would say keep an eye on it and if it happens again you should bring it up.