> Young children can acquire absolute (perfect) pitch — but adults cannot. The window closes around age 6.
I found some papers suggesting it is possible for adults, but more difficult.
https://pubmed.ncbi.nlm.nih.gov/31550277/
https://pubmed.ncbi.nlm.nih.gov/31686378/
https://www.researchgate.net/publication/388931575_Learning_...
You will probably claim it's not "real" perfect pitch, but many people use their tinnitus to help them. They identified their ring as having, for example, F#, and suddenly their relative pitch became absolute.
It’s not “real” perfect pitch. It’s more like training and memorizing. It doesn’t come as naturally as it does for kids.