Popping sounds in head?

Okay. So I have been getting these little popping sounds at the very top of my head, always in the exact same place. It sounds and feels as if a little bubble were popping in your head. Sometimes it will only happen once, but more frequently there will be multiple popping sounds, one after the other exactly a half second apart. I started getting them a couple of years ago every now and then but now they happen multiple times a day. I have looked online and saw that people have something similar but not the same. I'm actually pretty concerned. I'm looking for someone who has the same thing I do, not something similar. I'm really only looking for people who have some insight and who can give me more knowledge about it. If you can do that, I would be very grateful if you could reply. Thanks.