This months UC issue has a good piece reviewing various masks. This one caught my eye:
"Divers who suffer from ear troubles while diving will see the IST ProEar mask as a godsend ($100; www.istsports.com
). It encloses the ears and the nose within the same airspace (they're linked by tubes with oneway valves), so that the ears are kept dry in the same way and can also be cleared of water. The air space around the ears can reveal the underwater world to be a rather noisy place, but otherwise it really works."
So I went to the manufacturers website to learn more about such a unique mask design. At http://istsports.com/web/product.php?id_product=20080
"The soft silicone Ear Covers forms a water tight seal between the ear drum and the cover. The pressure buffer created to have the same pressure as your nasal cavity mask when air exhaled through the nose is introduced through the Equalization Tubes. Therefore the ear pressure in the middle and outer area is the same and the â€śsqueezeâ€ť from the ambient will be significantly reduced.
The part of that text that I show in bold does not make sense to me, and I do not see how the design of this mask can make it easier for a diver to equalize their ears (which is what the manufacturers website appears to be stating). A properly functioning regulator delivers air at a pressure equal to the pressure of the water at whatever depth the diver is at. If the diver has properly functioning Eustachian tubes, the middle ear pressure will be essentially the same as the pressure exerted by the water on the outer ear (on the eardrum).
If the diver does not have properly functioning Eustachian tubes I do not see how the IST ProEar mask culd make it easier for the diver to equalize their ears.
I have always had difficulty equalizing my ears and I have tried everything: decongestants, swallowing, pinching my nose and exerting pressure (mild) via my diaphragm, neck movements. And I can only descend with my head up: I cannot descend head down at all.
The only thing that works for me is to descend very, very slowly and clear frequently. I am always the last one to arrive at the planned depth. I also have to ascend very slowly so as not to get a reverse block.
It seems to me that the only advantage of the IST ProEar mask is that it keeps the ear canals dry and of you are prone to Otitis externa (infection of the outer ear, spelling corrected :-) it could reduce that. But using ear drops is cheaper and effective.