That’s a question about relative pitches, not absolute - you can definitely hear if e.g. the third is a little sharp or flat even if you don’t have perfect absolute pitch.
More generally, I think the answer is “pretty high-resolution”. Lots of people can definitely hear the difference between equal and just temperament.
IIRC most people’s hearing is accurate to around 10 cents (a tenth of a semitone). Wikipedia suggests musicians generally tune to within 12 cents, and the “just noticeable difference” is 5-6.
You’d only need absolute accuracy better than 50 cents to be able to correctly name a note on the piano. I’d guess most people with perfect pitch are more accurate than that, likely around the same ~10 cents mark.
Anecdotally, I have a musician friend with perfect pitch who finds it annoying sometime, as they find it unsettling when music is tuned slightly sharp or flat; so I think their sensitivity is much finer than a semitone.
More generally, I think the answer is “pretty high-resolution”. Lots of people can definitely hear the difference between equal and just temperament.
IIRC most people’s hearing is accurate to around 10 cents (a tenth of a semitone). Wikipedia suggests musicians generally tune to within 12 cents, and the “just noticeable difference” is 5-6.
You’d only need absolute accuracy better than 50 cents to be able to correctly name a note on the piano. I’d guess most people with perfect pitch are more accurate than that, likely around the same ~10 cents mark.
Anecdotally, I have a musician friend with perfect pitch who finds it annoying sometime, as they find it unsettling when music is tuned slightly sharp or flat; so I think their sensitivity is much finer than a semitone.