It is possible through exercises and concentration to develop your spiritual ears to a point where they will be more sensitive than they now are.
The first and most important step in this process is to concentrate on your ears while sitting in meditation or concentration at home. Give about one or two minutes of concentration to your ears each day.
During your concentration, hold the thought that it is your spiritual consciousness in your human body that you are directing to your ears and concentrating there so that it stimulates their functioning and power to the utmost. If you keep this up for about two minutes, you should gradually feel a sensation of warmth and perhaps a little tingling to the inner part of your ears. You might not sense this until after the third or fourth week of such concentration.
From that time on, you should feel the warmth coming to your ears very easily after beginning the concentration. From then on, you may notice certain slight sounds and impressions of sweet musical notes in the air, or a humming sound of a sweet tone occasionally coming from the atmosphere, when everything is quiet.
The moment you stop your concentration, you will not hear these sounds. But whenever you want to hear them, it should be possible to stop whatever you are doing for a moment and concentrate your attention on your ears and immediately hear certain high-pitched sounds, which will indicate that the spiritual part of your ears is functioning.
Remember that one or two minutes of concentrating your attention on your ears, as though you were putting all of your mental thought into them, unaware of any other part of your body, is all you will have to do. Later we will discuss another point regarding the ears.