I am a long time meditator. In the last few years I began to hear a straight line hum of a high frequency. My hearing is 100% perfect, I only hear the sound while meditating & it hum sounds the same regardless of where I am located on earth. What is going on?
From what you have described, it seems to me that you are tuning into the background hum of creation itself. This indicates a refinement of awareness and is a very good sign. there is nothing more you need to do or even necessarily learn from this experience. It is enough to have it and let it be assimilated into consciousness. It may even leave your conscious attention after some time, but don’t worry, because that does not mean you have lost what that access has brought to your consciousness, it only means it no longer needs to remain in the forefront of your mind, and you are ready to move on to another stage of growth.