Ears can be trained. Which is why every music school in the world offers ear-training courses. I suppose it should go without saying, but for musicians the ability to recognize fine distinctions among sounds is crucial. And what musicians are trained to do is to recognize very specific kinds of information in sounds, to recognize relationships and patterns and to be able to reproduce them.
They do this through practice and memorization. The distance in pitch between any two notes, for example, is called an interval. Well, musicians are trained to recognize intervals, no matter which two notes are involved, and to hear those intervals in advance, mentally, when they see those notes on a page, so that they can play or sing the notes correctly. With enough training, some very talented musicians can look at a complicated page of music and hear the whole thing, harmonies and all, in their heads, without playing a note.
This has been A Minute with Miles – a production of South Carolina Public Radio, made possible by the J.M. Smith Corporation.