That simply isn't true. First, a number of people I know have damaged their eardrums using Vasalva, hence I have become pretty adament at advising others to learn other methods for equalization. They are more difficult to learn, but they are safe. Vasalva is not. Just because you and I and millions of others haven't damaged yet (as far as each individual knows) our ears, doesn't mean that others have not and it is not without risk.
DAN does state in
6 Methods to Equalize Your Ears - Divers Alert Network the following:
the Valsalva maneuver has three problems:
- It does not activate muscles which open the Eustachian tubes, so it may not work if the tubes are already locked by a pressure differential.
- It’s too easy to blow hard enough to damage something.
- Blowing against a blocked nose raises your internal fluid pressure, including the fluid pressure in your inner ear, which may rupture your “round windows.” So don’t blow too hard, and don’t maintain pressure for more than five seconds.
I'd recommend searching for posts by
@Angelo Farina on this topic.
First of all, I was referring that it is not so easy to damage the eardrums from increasing pressure because someone forgets to equalize. Increasing pressure and ultimately pain are good reminders.
Nevertheless, regarding the Valsava method, I believe you've answered the first part yourself. The fact that Millions of divers + myself have not damaged our drums in many, many years should cover it.
I agree with the fact that there are other methods for equalizing but the percentage of people capable of doing so is really small and that's why the majority of the agencies stick to the Valsava method. I didn't said that divers shouldn't try those as well, I stated that at least for the beginning, sticking to things that work and simplify the task makes sense. I see no need to task overload students.
Furthermore, in any class I assisted, we show the learners the other methods and ask them to try them above water. As I said, a very small percentage is able to equalize consistently and convincingly with those methods while with the Valsava maneuver, not only the success rate is by far better but all students are able to recognize what is going on: 99%* of students trying the Toynbee technique (for those who don't know, it is based on swallowing saliva while pushing air to the back of your throat / up your nose with your tongue) didn't got a convincing 'pop' while with the Valsava, they can simply feel it.
I do like the Frenzel technique BUT this means that the students need to learn how to contract (open / close) the vocal fold instead of just pinching their nose and blowing... too much for a beginner IMO.
You can hurt yourself obviously if you don't equalize often and then try to force it by blowing air very strong but this is something one should avoid initially as you already know and probably teach. As simple as ascending a couple feet and trying again.
Closing, please don't scare
@Samson, he is just starting and feeling nervous as expected. He is not going to damage anything by using the Valsava maneuver, quite the opposite. Let's keep things simple and stress free for this new diver
* not actual percentage, just used to make a point.