I noticed this many years ago when I was in my early 20's. I went to the doctor, who did nothing, but eventually it went away.

Many years later I bought some of the cheap little ramen noodle packets that I had eaten when I was young out of nostalgia, and the sensation came back. Quaker breakfast bars have the same effect. So for me, I think this must be caused by some food additive. I'm not sure whether acid reflux is involved, but I wouldn't discount the possibility.

It might be worth trying to figure out if it's something you're eating.