I've been noticing an interesting phenomenon. During the music ear training, students of any instrument (piano, guitar, string, woodwind, brass, drums, voice, etc), who are not self-conscious, not self-judgmental, and having fun learning, do a lot better during the ear training than the students who are anxious, self-judgmental, and worrying about whether if their answers are going to be correct or not. And I've realized why this is happening, during their ear-training sessions, especially with the teachers. When they are trapped with their worries, of course, their energies will focus on their worries emotionally and psychologically without them knowing that's what's happening. Their bodies get tensed up. Their ears get shut down. But their worries get blown out of the proportion. There is no space for them just to listen openly and take it all in as it is without any judgment.
However, I'm not saying that these students are always bad at ear training at all. When they are in a relaxed situation, and when they are having fun, I'm sure they can also tune in to the sound very well. Their senses are more active, not their minds and emotions. We all hear the saying, "Smell the roses." It's the same concept.
It's easy for me to say to these students, "Drop your self-judgment," but it's not easy to achieve that. But if you are trying to train your music hearing, if you want to be able to hear the music better, you first need to be in the zone, be totally relaxed, and get rid of junk out of your mind to make your senses alive and more sensitive. One way to achieve this is to move your body around first, go for a walk, or exercise a little first. It'll stop your thoughts and judgments at least temporarily. Then, try your ear training. It sounds very simple. But you'll be surprised how effective it is and how much better you are going to be able to hear.