Students need to hear and determine pitches and note intervals. On the guitar, I always use an exercise to help the student learn which string to play.
I turn my guitar toward me, and, starting with the first open string, I play it as I say “1st string” and have the student play and repeat the same. I do this, in order, for all six strings.
Next I play the first string and the student has to determine what string I played and play the same string. I usually play the strings in this order: 1 2 1 3 1 4 1 5 1 6 before playing random strings. If the student plays the wrong string, I keep playing the string until they play the correct string. I then play adjacent strings, bouncing back to the string that was played incorrectly, before continuing the exercise.
This training has improved the students’ ear as well as helping me differentiate between students with a good ear and students with a poor ear.
This exercise can be done with any instrument, including the voice. You will be surprised how many students, no matter what their age is, get a perfect score.
Good ear and good hearing, these are very important factors to musicians. In the music the biggest roll is playing our ears. It listen to music and identify all variations. So eat training is must for musical student.