Hello; I am an Audiologist.
Since your only reported complaint is the noise, and you only hear it when you touch the area and change the shape of the external ear canal, it is most likely a buildup of ear wax that is not fully occluding the ear canal.
As @rooeytoo mentions, there are drops available that can soften the ear wax. Here in the US, they are available without a prescription… but I seem to recall that you are not in the US.
However, since I have the impression that you have not experienced this before, I would highly recommend having your ears examined by a physician before you put anything in there.
There are other possible causes of your symptom (including insect invaders; and yes, I’ve seen a few in my day), but since you say the hearing is fine and you don’t mention any discomfort or dizziness, the wax seems most likely.