I posted this in the general help forums, and had no luck finding an answer there, perhaps this would be a better location (and I'm going to get impressions done tomorrow afternoon so I'd love to know more about this)
I'm curious as to how the shape of the ear changes with relation to jaw position and movement. If you have impressions taken in a mouth-fully-open position, would the resulting CIEM's potentially be uncomfortable with a closed, or slack jaw? Does the ear canal simply expand, or does she shape change significantly enough that there's a limit to how wide open your mouth should be during the impressions?
I've owned a pair of Unique Melody Miracles for about 7 months, and sometimes if I'm walking around I'll hear a slight popping noise which, I'm assuming, is the result of a momentarily broken seal, on every step I take, and sometimes massaging my ears around the CIEM helps alleviate it, and sometimes it doesn't. I've also had moments where I'll yawn and for about half a second, the music I'm listening to becomes louder and, it seems at least, slightly clearer. I had the impressions for these taken in an open-mouth position, with my mouth about halfway open, using a bite block.
I'm currently saving up to buy a Noble 5S custom silicone IEM, and I seriously wish I had heard of Noble before I had bought my UM Miracles. I was originally hoping, before I bought them, to buy a set of Spiral Ear silicon CIEM's, but the impression instructions for them required a closed mouth, and I was told by Spiral Ear that my ear canal was too small for anything more than their dual-bore design, which only used 2 BA drivers, if I recall correctly, so I looked elsewhere at the time. Now that I'm planning on buying a silicone CIEM as opposed to an acrylic one, I'm trying to figure out what the best way to get the impressions is. My only concern is that, if my mouth is too open during the impressions, the sound bores may be compressed during periods where my mouth is closed, and the flip side, that if my mouth isn't open enough, that having a silicone CIEM won't alleviate the problem I'm having of periodically broken seals as I move around.
Also, I wanted to ask about cable noise. With my Miracles, slight movements of the cable, especially if it's brushing up against something (such as my collar, or the zipper on my jacket) is very audible in my ears. Is this simply a property of hard acrylic transferring vibrations much more effectively than softer silicone? Does this have anything to do with the quality of the fit in the CIEM? And are silicone CIEM's less susceptible to this issue than acrylic?