It's the same thing mechanics use to identify engine sounds quickly or why some people can tell who's walking on a hallway because of how the steps sound. Repeated exposition to a stimulus that then gets associated with something etches a memory.
This not only happens with perfect pitch. To for example know how to tell a major third from a minor third on all keys you can "memorize" all the sounds and know which one they are. I think my brain kinda did that and now I sometimes get confused with M3 and P5 because of how "similar" they sound even though you can like totally fit another tone comfortable between the root and the fifth and the root and the third don't have enough air for that.
If you are interested, see Chapter 3:
> Participants got significantly more trials correct when the timbre of the trials was congruent with the participant’s primary instrument (M = 39.13 (out of 48) trials, SD = 11.26) as opposed to incongruent with it (M = 36.5 (out of 48) trials, SD = 13.7), [t(23) = 2.935, p < .01].
Curious if this happens to others - you’ll hear a noise (e.g a glass hitting something, an object falling to the ground etc) that makes a single tone, and a song immediately starts playing in your head because it starts with that same tone?
My stand up desk at an old job was the starting pitch to Beyoncé’s Crazy in Love
minor 2nd : Jaws
major 2nd : Frere Jacques
...
Now every time I hear an interval these things enter my brain.Yep... intervals helped during music exams :)
I remember noticing in highschool that hitting a few different corrugated plastic gutter pipes in my backyard would allow playing the bass line to Crazy Train...in principle, i immediately recognize the notes to different beeps and alarms in daily life and think about it unconsciously.