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Questions about quality of fit in acrylic vs silicone CIEM, impressions, and cable noise

post #1 of 12
Thread Starter 

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?

post #2 of 12
If you are planning to buy noble products, I suggest you ask in the noble thread in the portable headphone section. The doctor that owns the brand is a regular poster there and is quite active in explaining this type of questions. I recall a similar explanation about this issue somewhere in the thread.
post #3 of 12
Thread Starter 

I'll look through the thread but I figured with the amount of questions I had, making my own thread seemed like a cleaner option, along with googling of course

post #4 of 12

I think a pm to average joe might be the best option. he has a great deal of experience and is such a nice helpful guy.

about cable noise, the cable itself has some responsibility in it, some cables will transmit more noise than others.

but silicone probably absorbs a good deal of vibrations so it should help.

post #5 of 12
Thread Starter 

Thanks for the advice, I just sent a PM to him. 

As for the cables being responsible, I have a feeling you're right. I switched to a different cable with my Miracle's, the memory wire section is much softer and more flexible, and while it didn't eliminate cable noise entirely, I would say it cut it in half. Perhaps a quality cable with a silicone CIEM would eliminate it almost entirely? Fingers crossed!

post #6 of 12
Well the founder of noble is the one that holds a doctorate, your choice but if you dont mind, can you post your findings in this thread? I know the noble thread is massive. It would help other people find the answer to the same questions easier.
post #7 of 12
Thread Starter 
Quote:
Originally Posted by KamijoIsMyHero View Post

Well the founder of noble is the one that holds a doctorate, your choice but if you dont mind, can you post your findings in this thread? I know the noble thread is massive. It would help other people find the answer to the same questions easier.

I emailed noble support directly instead, not sure if I'll get a reply by the time I have my appointment but fingers crossed. I'll definitely post what I find out, it's annoying hunting through hundreds of pages for a relevant post :P
post #8 of 12

I have always provided closed mouth impressions for silicone CIEMs, but the manufacturer recommendation is what needs to be followed.  Manufacture processes may be different from manufacturer to manufacturer, so making the impressions per the instructions is important as they can make adjustments such as tapering the canals.

 

With that said, the most important thing IMO for impression taking when they are being made to the mfg instructions (open or closed mouth) is to get as deep of an impression as possible.  The deeper the impression, the more accurate your canal will be.  My first set of professional impressions was not deep enough and resulted in a bad fit.

 

As far as keeping a seal while moving, silicone shells are better than acrylic from the standpoint that they don't need quite as perfect of a fit.

 

Microphonic are primarily cable attributes and not the CIEM.  Occlusion is hearing your footsteps resonate through the shell and is in large part due to ear anatomy.

post #9 of 12
Thread Starter 
Quote:
Originally Posted by average_joe View Post
 

I have always provided closed mouth impressions for silicone CIEMs, but the manufacturer recommendation is what needs to be followed.  Manufacture processes may be different from manufacturer to manufacturer, so making the impressions per the instructions is important as they can make adjustments such as tapering the canals.

 

With that said, the most important thing IMO for impression taking when they are being made to the mfg instructions (open or closed mouth) is to get as deep of an impression as possible.  The deeper the impression, the more accurate your canal will be.  My first set of professional impressions was not deep enough and resulted in a bad fit.

 

As far as keeping a seal while moving, silicone shells are better than acrylic from the standpoint that they don't need quite as perfect of a fit.

 

Microphonic are primarily cable attributes and not the CIEM.  Occlusion is hearing your footsteps resonate through the shell and is in large part due to ear anatomy.

Why are closed mouth impressions preferred for silcone CIEM's? Is there a risk of the sound bores closing or restricting the audio quality, while you're listening with a closed jaw, if the impressions are done open-mouth?

Noble just has the instructions for an open-mouth impression, I'm not sure if that's just for their acrylic products or if it applies to both their silicone and acrylic lineups, it doesn't say, so i got my impressions done open-mouth, and I'm just hoping that the CIEM I eventually recieve has a good seal 

I know about occlusion, and that's not something that's problematic for me for the most part. The problem I have is an actual popping noise on every step I take, usually every right step, and in my right ear (I have a feeling my left ear has a better fit than the right one for my Miracle's). Are there any properties to cables that are known to affect microphonics, such as being braided or wrapped, or the presence/quality of the memory wire?

post #10 of 12

usually I think closed mouth makes the jaw to obstruct slightly the ear canal, for others the jaw is actually helping keeping it in "shape" (depends on you, and also where your teeth are ^_^).  recommendations are made based on the majority.

it doesn't really matter if the impressions are done open or closed per se, what matters is that the guy working on it knows which it is. and ofc if they're used to do molds from closed mouth, the part they might decide to reduce slightly for comfort will not be at the same place if they know the mouth was opened(think jaw bone moving one way or the other).

your audiologist can tell you all that, but mostly what counts is simly correct information.

post #11 of 12
Quote:
Originally Posted by InternetSandman View Post
 

Why are closed mouth impressions preferred for silcone CIEM's? Is there a risk of the sound bores closing or restricting the audio quality, while you're listening with a closed jaw, if the impressions are done open-mouth?

Noble just has the instructions for an open-mouth impression, I'm not sure if that's just for their acrylic products or if it applies to both their silicone and acrylic lineups, it doesn't say, so i got my impressions done open-mouth, and I'm just hoping that the CIEM I eventually recieve has a good seal 

I know about occlusion, and that's not something that's problematic for me for the most part. The problem I have is an actual popping noise on every step I take, usually every right step, and in my right ear (I have a feeling my left ear has a better fit than the right one for my Miracle's). Are there any properties to cables that are known to affect microphonics, such as being braided or wrapped, or the presence/quality of the memory wire?

 

Typically (and since we are human, there is variation and no hard rule), the ear canal is larger when your mouth is opened than closed, and ear canal size is also dependent upon head position.  An example with that experience I have had is wearing CIEMs on a plane.  They are fine when I am sitting up, but when I lean back or chew, the seal breaks.  When the seal breaks, I can hear outside noise and the bass response decreases/general sound quality is worse.

 

While a manufacturer may be able to answer the close vs. open impression question better, the flexibility of silicone will allow for the impressions to adjust to your ears as you sing, eat, and move around.  The sound tubes are not affected, at least sonically to my ears, during this movement.

 

It goes back to the way the manufacturer wants the impressions since the technicians making the shells make their own adjustments, so they request the impressions be taken a certain way.  I would get a confirmation from the manufacturer before taking any ear impressions if you aren't sure.  But, even if an audiologist makes ear impressions to the manufacturers instructions, their skill/technique and your ear can make a difference in final fit.  Here are some reasons:

- Impressions aren't taken deep enough, therefore the canal won't be thick enough

- Your ear isn't typical, and is larger with your mouth closed than open, which can lead to canal pain.

- If you have issues with your ear or are sick, your ear canal could be smaller than normal

- Large weight change or level of hydration (dehydrated) could change your ear canal size.

 

That may all sound scary, but typically, if the impressions are taken per the manufacturer's instructions and from a good audiologist, there will be no problem.  All manufacturers do offer a refit period, so knowing what to test early will help you know when to send it back for a refit.  Sometimes shells made from the best impressions can require a refit.  I always take my ear impressions the same way, and even take multiple impressions if I think they are less than perfect but still don't always get the best fit.  Some examples: my first set of Perfect Seal CIEMs had too much of a taper in the canal while Minerva impressions are extremely tight, tighter than anything else I have without discomfort of pain (and both acrylic and silicone were made from the same impressions).

 

If you had your Miracle refit, you may like it more, but the bottom line is whatever you do get, make sure it fits properly within the first month, and if not, get it fit right.  You have to think of it as a long-term investment and spending the time initially to get it right is important.

 

About occlusion and microphonics: I don't really experience occlusion, and it is different than microphonics.  Occlusion is more about the ear anatomy combined with the fit of the IEM/CIEM while microphonic are transferring of noises along the cable.  Microphonics is difficult to predict by just by looking at a cable as stiffness, cable makeup, and memory wire configuration play into it..  

 

In your case, try wearing the CIEM shells without the cables and see how that changes anything and let us know.

post #12 of 12
Quote:
Originally Posted by KamijoIsMyHero View Post

Well the founder of noble is the one that holds a doctorate, your choice but if you dont mind, can you post your findings in this thread? I know the noble thread is massive. It would help other people find the answer to the same questions easier.

+1. Thanks.
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