Decided to investigate further what makes a (ReSound) mold stay in so well. It does appear that the top of the mold indicated by the red arrow in the previous picture is deliberately caught below my crus helicis - arrow #1 in picture below. But there appear to be two further features (at least!) that aid in retention. #2 is that the springiness of the receiver wire embeds itself a bit into the inside of my tragus, creating additional friction against movement. #3 is that I mentioned in my previous post above, the removal knob and plastic string have a certain springiness and they are also bent against the inside of my tragus with the knob just sticking down below the bottom edge of the tragus (little pearly blob). The stiffness of the plastic “thread” pressing against the inside of the tragus/concha valley restricts movement. I don’t feel any of this. I have zero sensation of anything in my ears talking, chewing, yawning, whatever. And I am a relative scrawny, -er, “sinewy,” guy so it’s not like I have a tremendous amount of adipose tissue for stuff to dig into.
So my mold impression when taken filled the whole concha area and probably the cymba of concha area, too (at least - see figure in post I’m replying to). I guess that gives the folks who actually design the mold from the impression a good idea of what in your ear canal and concha region that they can use to make a mold that will actually stay in your ear canal. I guess the bigger the mold you might need to keep things in place, the bigger the impression required.
Another neat thing about having a translucent silicone mold that has no color is the mold “transmits” the darkness of the interior of my ear canal to the outer surface of the mold. So one just sees the ear canal as a “dark place” with a wire running into it.
Edit_Update: Earmolds and More: Maximizing Patient Satisfaction
