Acrylic vs titanium earmolds

Hearing Aids
#1

I sent the following to my audiologist (including article written by Phonak audiologist):
https://www.hearinglikeme.com/hearing-challenges-solved-with-titanium-hearing-aids/:
“Titanium 3D printers are more precise and have lower tolerances than the standard acrylic printers and can result in a better fitting device. When your hearing aids fit properly, they are physically comfortable day in and day out.”
“Due to the strength of titanium custom shells, they can be printed at HALF the thickness of acrylic. The walls of the shell reduce from 0.4mm to 0.2 mm. With 0.2mm thinner walls, that added space can be used to make a bigger vent, and will result in less occlusion.”
" A thinner shell is designed to allow for deeper placement in the ear canal, helping to give users a more discreet fit."
It seems like a significant benefit that Phonak would have more space to optimize the various shape/acoustic parameters of the earmold for my extremely challenging ear canal and hearing loss.

Her response:
The printing of the earpiece is irrelevant. Acrylic molds are 3D printed as well. (Of course, a Phonak sponsored blog is going to say their product is the best; its marketing). It still requires a new impression be taken of your ear. All earmolds are created based on the impression of your ear that is sent in. It could be that the anatomy of your left ear is just not conducive to an appropriate fit earmold of any kind.

I’ve been back and forth about this multiple times, she still doesn’t seem to understand the difference. Any advice? Anyone have access to more opinions or evidence that might get her to pay attention? Thanks

#2

What’s particularly challenging about your ear canals? I’m guessing titanium’s main advantage would be for those with very narrow canals and those needing a relatively big vent. With acrylic, if there’s a particularly spot that’s causing discomfort, it can be modified in office. If you really want titanium, it sounds like you need to go somewhere else. If you otherwise like the audiologist, you could tell them this: “I really want to try the titanium mold. If you won’t do it, I’ll go elsewhere.”

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#3

Left one is just incredibly hard to fit, either retention fails or too large and painful. Countless office modifications have failed, so no interest in that. I expect it to be manufactured with a proper fit. The titanium printer has lower tolerances. Imagine a mill that can cut your boards to 5" or 6". Then there is another mill that offers 5.1", 5.2", 5.3" etc. It’s a subtle difference, but it makes sense that that could significantly affect the fit in an ear canal, does it not?

#4

At first thought, yes it’s intuitive, BUT if the issue is the correct dimensions, the mill that can cut you a 6 inch board should be able for somebody to sand it down to even finer tolerances. If you have retention issues, something like a skeleton mold usually does the trick and I doubt titanium is available in it. I used to have silicone molds with a canal lock, but had feedback issues as they would migrate out ever so slightly. Acrylics with skeleton mold did the trick

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#5

Aside from the wall thickness, does anyone know if the faceplate falling off issue was ever properly addressed by Phonak?

#6

I agree on the skeleton type mold having amazing retention. I just picked mine up last week using silicone instead of acrylic. They are a slight hassle to put in my ear and i have to use a mirror to do so, but once in, there are locked into place and dont budge. I have pretty high gains in my bad ear and have zero feedback even if i lay my hand on over my ear. I tried the other styles in both acrylic and silicone and wished i had tried the skeleton type yeard ago.

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#7

They get easier to put in over time. I needed a mirror at first too!

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#8

Sanding to “finer tolerances” is pretty useless (as I’ve experienced 10+ times), because eyeing it with a grinder will never be remotely as accurate as digital models and 3D printing

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#9

Yeah, I think so. I haven’t seen it happen in a while. We also saw huge growing pains with the fits coming out of the titanium lab when they were first out, some really challengingly painful or just weird shells, but that seems to have been largely resolved as well.

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#10

What exactly is the problem with the retention? If your ear is just a straight shot down to the floor with nothing to catch on, which can be the case with certain anatomies, titanium probably isn’t going to fix it. Additionally, if you have a lot of motion in your jaw paired with sensitivity in the canal if you push into the jaw (sometimes associated with grinding or TMJ) it can be hard to make a hard mold comfortable.

Titanium might help if there are size issues for fitting in the desired receiver or vent, but that doesn’t sound like the issue?

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#11

And any ‘human finishing/buffing’ always takes down the high spots first, irrespective of whether that’s what’s needed in the process.

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#12

How I insert my mold without mirror is to get the basic orientation of the mold correct and insert into the ear. Then push the skeleton part into place. Then place hearing aid behind ear.

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