[penbat]

When i asked my audiologist for a set of open-mouth impressions she was comfortable with that idea but automatically asumed i would have a set of closed-mouth impressions to go with them.

Yes i can understand that with open mouth impressions the seal is likely to remain intact if i yawned. But surely if the mouth was in a normal postion (which would be most of the time) closed-mouth impressions would give better results.

 

[Welly Wu]

Penbat:

If you want to know why Ultimate Ears mandates an open mouth ear impression, then why don't you ask them directly? Report back with your findings.

 

[Tyson]

With my Sensa's I initially had closed mouth impressions made, and the fit was not good, even the slightest movement of my mouth (smiling, talking, chewing), caused the seal to break. My second set of impressions were open mouth and the resulting fit was MUCH better in all positions.

 

[JB.]

Having looked into this a bit, and after contacting every company I could find before finally settling on Westone for my mods, I have a possible answer.

The mods created from ear molds are made of either hard or soft material. Hearing professionals typically take a casting of an ear, send it off to a company (i.e. Westone) who create the hearing aide, music-plug, swimplug, etc. directly from that cast. The device is then sent back to the hearing professional who then shows the patient how the earpiece should be worn. About 10% of the time (a figure I'm quoting from my audiologist) the earpiece is not an exact fit, and a tool (her office uses a specially designed "bench-grinder" and a Dremel) is used to smooth or remove areas in order to produce a perfect fit.

In the case of soft mods, nothing can be done to the earpiece once it has been cast. If it doesn't fit, you have to retake ear molds and send them off again. I asked Westone about this before deciding to buy my mods from them they told me I could simply send in the faulty mod with a second cast and they would make another mod for me. If the earpiece is not identical to the ear canal there will be problems:
1. Too big = discomfort (the level of discomfort varies, but the earpiece can still be used)
2. Too small = no seal (without a seal, the earpieces are useless)

Now for my rudimentary knowledge of the ear canal. The canals do enlarge a bit when one opens one's mouth. The wider you open, the greater the increase in the size of the canal. So, by taking an open-mouth mold, you are more likely to prevent the earpiece from being too small and therefore unable to create a seal. However, the ear canal does not simply increase in volume as you open your mouth. The SHAPE of the canal changes as well.

SO, if one takes an open-mouth cast, they will most likely have an earpiece that creates a good seal, but not necessarily have a perfectly comfortable fit.
If my audiologist's figures are correct, by requiring customers to take open-mouth casts, UE will avoid seal problems on a large proportion of their earpieces, but at a potential cost in comfort.

 

[lindrone]

Correct... when you open your mouth wide, the size of the ear canal increases.. thus by taking a mold with your mouth wide open, you are ensured your custom IEM will fit completely. However, it will be tight when your mouths are closed.

The other way around, the seal will break whenever you talk or sing along with the music and whatever.

That's why there's the "full-soft" option for UE's.. and silicone material for Sensaphonic. They allow for less fatigue over wearing a long period of time by allowing flexibility when your canal "squeezes" on the custom IEM when your mouth is closed.

This is also why I think material is of utmost importance... of course all of them are better than any universal fitting canalphones. Wearing them for extended period of time though.. say.. 5 hours or something... or perhaps even doing it for a couple hours a day for a matter of weeks will start to show on you.

The different between hard and soft material isn't so clear at first either.. but it'll show over time.

 

[penbat]

This is what Mindy said about this:

"From a manufacturers point of view we request an open mouth impression
with a bite block inserted the entire time for consistency. Each
audiologist or hearing aid dispenser has a different opinion as to what
is the best technique. Most are still not that familiar with our product
and are using their experience with hearing aids or earplugs as the
basis for their opinion. We have taken the option of the experts quoted
on our instruction sheet and from our own experience as a manufacturer
as to what produces the best end result for our clients and our product."

 

[penbat]

Quote:

Originally Posted by penbat This is what Mindy said about this: "From a manufacturers point of view we request an open mouth impression with a bite block inserted the entire time for consistency. Each audiologist or hearing aid dispenser has a different opinion as to what is the best technique. Most are still not that familiar with our product and are using their experience with hearing aids or earplugs as the basis for their opinion. We have taken the option of the experts quoted on our instruction sheet and from our own experience as a manufacturer as to what produces the best end result for our clients and our product."

Not sure about "a bite block inserted the entire time for consistency". I had one ear done at a time with the audiologists bite block on the side where the mould was being taken. Its difficult to keep your mouth still for both mouldings in one hit. In fact my first moulding for the right side (done after the left had been done) was not deep enough so it had to be done again. I suspect that there is bound to be a certain amount of inconsistency between the amount my mouth was open between doing the left and right impressions.

 

[Big D]

Quote:

Originally Posted by penbat Not sure about "a bite block inserted the entire time for consistency". I had one ear done at a time with the audiologists bite block on the side where the mould was being taken. Its difficult to keep your mouth still for both mouldings in one hit. In fact my first moulding for the right side (done after the left had been done) was not deep enough so it had to be done again. I suspect that there is bound to be a certain amount of inconsistency between the amount my mouth was open between doing the left and right impressions.

I think she means that the mouth does not move while each impression is done. It should make no difference if there was a difference when each impression is done, just that moving the jaw while the impression is being made will affect its quality.