20/20 Hearing

Wonder if my hearing is up to 'par'...... is there 20/20 hearing what does that sound like?.. what is optimal listening do i need hearing aids?????

I often wonder how much hearing I have that is damaged (if any)- I've been to a few concerts in my day........ Way too close to speakers...... So just got thinking about this. 20/20 Hearing- does it exist ?