Don't take "sense of hearing" literally

I mean in a different way...




I don't remember where I got these chords from(I'm pretty sure I picked them up from some song), but there starting to sound like they clash to my ears. I think my perception of hearing is changing.

Do these chords sound right?

Eb7 Add 9 and b13
Db7 Add #9 and b13
Ab7 Add b9 and b13
A7 add b13

I use these chords all the time when I improvise. Are all of these actual chords?

Seems to me that when we play dissonant chords in the upper registers of the piano, they are more likely to clash to our ears. If we play them in the lower registers of the piano, they sound better. Why is this?

Another thing is that some chords sound clashing when they are not in context with music, but when they are in the context of the music they sound good. For instance, when I play A7 Add b13 alone, it doesn't sound that good, but when I play an A7 Add b13 to a Dmin9 chord progression, the F(b13) of the A7 leads to the E(the 9th) in a Dmin9 chord, and it sounds good. Strange?