Before I found this forum, I thought there was something wrong with me. Whenever I'm in a relatively quiet environment, I can hear a high pitch sound in both ears. It is very hard to characterize it but it has softness and mild noise in the background, maybe somewhat comparable to the noise generated by a river. If light had sound, I think that would be it.
So I was doing breath meditation and decided to investigate the mysterious sound. I was watching it and got absorbed for a few moments. Waves of energy started going from the spine up to the chest. Then I got too excited and started thinking, which ended the absorption. Later I could not repeat it because I was too intentional. I will try again one day when my concentration improves. But it is a very interesting discovery thanks to this forum.
BTW, my hearing gets tested regularly due to my line of work so I know I don't have any medical issues.