A diver avoids an ear injury through correct procedures and good buoyancy control
I was an assistant instructor with a group of three students, one instructor and a divemaster for the deep dive. At the end of the dive we ascended and I experienced a reverse block in my right ear. I descended again until it was relieved and then very slowly started ascending again. I was not able to clear it for about 10 minutes. Several times I had to descend and then try to ascend again. Even when I managed to clear it such that I could surface without severe pain, my right ear was still very sore. The next day, I got an appointment with my primary care physician in the afternoon. He sent me to an ENT. The ENT said that the eardrum and Eustachian tube were fine. They performed a pressure test on both ears, as well as a hearing test. Everything appeared to be fine and my hearing was very good in both ears.
A reverse block can happen even when everything else went well in a dive and this diver followed the correct procedure by re-descending to take the pressure off. By re-descending, then slowly trying to ascend in small steps, taking the time to let the trapped gas work its way out, this diver avoided a burst ear drum. This is another example where excellent buoyancy control can make the difference between avoiding an ear injury or suffering one. Remember, the correct hand signals for this are "Something is wrong" followed by pointing at the problem ear.