This is the way. Most people don't have 'absolute perfect pitch' but, almost anyone can train themselves to have relative pitch, which can mostly give the same

This is the way. Most people don't have 'absolute perfect pitch' but, almost anyone can train themselves to have relative pitch, which can mostly give the same result. That is when you are given a good starting point to refer from, you can then work out where something is relative to that starting point. That's why tuning forks and pitch pipes exist. You need a source of truth to ground things in, and then you can train yourself to hear the relative distance between notes from there.