Holy nad. The unstruck sound. That's what the Buddhists and eastern gurus call it. You can change the pitch of the ringing in your ear through meditation. In the west, it's a pathology, in the east it's a blessing. Go figure. When a person begins to develop spiritually, the sound appears automatically. By concentrating on the sound, you can increase the volume, change the pitch, and use it to alter states of consciousness. Of course, if you're not interested in psychic phenomena and altered states of mind, then its just a problem, and a nuisance. The same with all siddhi powers, they are completely disturbing to those who just want to lead an ordinary life, like most other people. When the kundalini awakens in the unprepared individual all these unusual manifestations begin to appear. You could research all these things, and develop a liking for the phenomena, or you can adopt the view that it's a problem that needs medical treatment. But, be aware, anything the west doesn't understand, is considered a pathology, something to be fixed with medication or treatments. If you want a balanced view, find a spiritual guru, get some answers on the other side of things, see a different point of view.