I'm a bit confused about the technique here - you're saying that you open the tubes and then you use pressure, such as with Frenzel - to equalise. Do you mean that with the tubes open you don't need to pinch your nose in order to force air into the tubes? So, if you were dry and without a mask then would it also work? Or do you need the partial resistance that a mask (or water) offers against your nostrils in order for it to work?
Also, in terms of the external noises getting louder or muffled - if I Frenzel right now, then the noises definitely get muffled. But if I do it really, really lightly then the first effect, right as it feels like the tubes are opening, is the same as when I'm contorting my face to try and get them open hands-free.
However, one possible give away - I find it hard to hum and release the muscle I need to release in order to get that feeling: does anybody else have that difficulty?
Yes when I dive I don't pinch my nose to equalise. I just open the e-tubes and push a small amount of air up using frenzel and if I do this all the way down it seems to get enough air into my e-tubes to equalise. It's not like when you pinch though and a lot of air goes in at once, it's like 'topping up' the e-tubes with a bit more air very often. I only pinch once on the surface before I dive and equalise just to help open my e-tubes and with the equalisation in the first couple of meters. (reduces the pressure difference)
I used to think that this would only work with a mask after reading here that people equalise 'against the mask' and I thought I was doing the same but then I tried doing a shallow dive (5-6m) without a mask and I could still equalise fine without pinching my nose, so my conclusion is that the mask has nothing to do with it.
I really don't know if what I am doing is ok etc - i wasn't taught to do it this way or anything, I just couldn't equalise for the first couple of years (especially my right ear) using any other method and this the only method I've found that works for me. I still cant equalise head down if I pinch my nose, no idea why! Maybe if I practiced that I would get it but I like hands-free anyway so I don't think I'll ever go back to pinching my nose unless there is a reason.