Are some people just unable to wear custom molds?

After four sets of ear molds from two different manufacturers (Phonak and Westone) I am beginning to think that I am just not able to wear molds.

I have yet to get a comfortable pair, usually my left ear the molds are painful, the one that wasn’t would not stay in.

My audiologist said that I have ‘deceptively small’ ear canals. Because of how small they are acrylic molds would not work so we have working in trying to get a working set of silicon molds.

At this point I am thinking I may just have to give up and go back to domes even though it will mean not being able to meet my full prescriptive gain.

Anyone else have similar issues?


Please, explain what kind of molds are the one you tried? Example, canal-lock, canal-ear-molds, shell-ear-mold. And is it bte? or receive-in-the-canal?

I didn’t have any issues with discomfort, but getting a proper fit and venting has been a challenge. I think I’m also on my 4th try. Biggest issue was getting venting right to be able to get enough gain without feedback. Also some issues with them staying fully in. Even with canal locks, they back out slightly. But, they’re comfortable and I get a decent amount of gain and no feedback. I’m guessing there’s a mold out there that will work for you, but it might take more effort than you want to put into it. Has the person you’re working with consulted with Phonak to try to figure things out? Frustrating that it’s the left ear that’s the challenge in that’s the one that could benefit most.

Molds can be problematic @zuikoholic as you are acutely aware… In the past I have usually kept the impressions, once I got a good fit, I did not need another impression done. @Um_bongo said he uses a cigarette lighter, and wet wipes to take down tight fitting molds, I will give that a go at some point… I believe Phonak in the UK use a 3D printer to make their RIC molds? I am at present awaiting a new left ear silicone mold, this was giving me a fair bit of pain, if it is still defective I will try Um_bongo’s method. Cheers Kev :wink:

@zuikoholic: This may be a dumb question. It’s certainly not based on my personal experience with hearing aids, but it worked when I had my instrument repair business.

If you were to powder the mould with talcum and insert it in your ear canal, would any high spots rub the talc off the silicone to give a better indication of where it needed to be knocked down?

[I’m only asking because sometimes it’s easy to overlook simple hacks like this - no offense to those members who are genuine experts in these matters.]

Aside from the size of the canals, why moulds?

The venting you’ll need would be 4mm + to avoid occlusion. I can’t see that fitting down the sides of a receiver unless they do something special.

Can’t you just get a custom receiver canal tip made?

I like the ‘engineers blue’ thinking in this.

Unfortunately most of the wall will be in contact, but you’ll get no idea of the relative pressure at a given point whether that’s caused by an underlying structure or an oversized mould.

Mould making is a skill; you’ve got to consider the taper to, and the absolute physical space at any given circumference of the section you’re looking at.

So in practice you can make a very short mould wider than the canal for retention by including collating ridges; assuming there’s enough give in the underlying pathology, but you can’t make the whole thing bigger by volume.


@Um_bongo: Thanks for your reply. And I do, in fact, understand what you’re alluding to (I’ve had this discussion with my audi re my ever-so-slightly mobile left ear mould, and he explained it similarly.)

My talcum/engineers’ blue suggestion was directed at the DIY “torchers” who may wish to refine their “torching target” :joy:.

Thanks again for sharing your expertise with us!


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As a newbie reading about these problems with custom molds seems the opposite of what I would expect. Right now I’m using open domes, and from a gearing perspective they’re fine. No irritation from them, but I find myself having to reseat them at least every hour. They seem to move about and even back out a little bit, although they’ve never fallen out. I would have thought getting molds made specific to my canal would eliminate that problem as they would be custom to my ear canal and be comfortable and stable. Yet it seem I’m wrong.

I’m seeing my Audi today and asking fir a selection of domes in different sizes to play around with. Hopefully one size will fit best. Are domes usually generic for receiver in ear, or do you have to stick by a brand name for proper sizing to attach to the receiver?

Some brands interchangeable; some not. Be careful to securely seat the dome. It is not uncommon for them to become dislodged in the ear.

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I wear custom ear molds and find them very comfortable. But before my OPNS1 aids I had worn mostly ITE aids for almost 15 years. I have always had an issue with my left ear mold slipping out a slight amount. I have said I must be lopsided because my right aid hasn’t ever been an issue.


Yeah Jim, I probably have at least 10 old sets of moulds, I am a fairly dexterous person, so new skills come quite quickly, but I have plenty old ones to practice on :upside_down_face: the problem with sanding moulds down is, it leaves the surface rough, Um_bongo’s method appeals to me, as I have used the sanding method on many occasions. It is better to wait a few days until the swelling goes down, if you are going to alter your moulds, finding that happy medium is perhaps trial and error, if you take too much off, you get feedback, too little then you are still in pain! A little at a time is the way to tackle this… Cheers Kev :wink:

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I don’t think that @zuikoholic’s ongoing problems are typical. Yes - initially, it can take a couple of tries to get it right, but once a good mould has been struck, it fits with comfort, stability and superior acoustic coupling.

I wouldn’t be dissuaded from moulds by reading one problematic account.

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RIC, I have tried basic canal, canal-lock and skeleton molds.


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I would say Jim… that’s not quite correct, RIC custom moulds are in my experience, easier perhaps to make, and nearly always fit fairly snugly with little or no problems… full shell or skeleton shell BTE custom ear moulds can be highly problematic, I don’t know who made the NHS ones, but it was rare to get a set that fitted correctly, you might get one okay, but the other would be bad, or extremely tight fitting, hence I said previously about keeping the good impressions, and just handing them in. I would say, it also depends who’s actually taking the impression, not to mention who is actually making the mould, it’s a highly skilled job, apart from the 3D printer ones! Cheers Kev :wink:

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Yes my Audi has, without a positive outcome, that was when we tried the Wesone molds.

Not sure what size the vents are but definitely smaller that 4mm, the current (West one) are smaller than the Phonak. There is some occlusion but I didn’t find it bothersome on the Phonak. The latest set
haver very small vents and they are taking some getting used to.

With domes we had feedback issues whenever we got close to my prescriptive target (based on REM) Phonak P70R aids.

We tried simple custom tips first but they just would not stay in, again the left ear being the most problematic.

Might have to give something like that a try.


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@zuikoholic: I’m wishing you good luck for a satisfactory outcome, Jim.


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Just got back from the Audi. We played with a few domes and it turned out I just have a wide canal. We found an open done that fits beautifully (after I jamb it in) with no rubbing so far. Hopefully that’ll be the end of my adventure on getting a decent physical fit. We also did a little more tweaking on bringing a few channels down a tad (it’s channels, right? I have no idea how the software works) and cleaned up a music memory setting so all seems good here.

I will keep molds in mind for the future should I ever need one to imprint hearing. It’s interesting to read about different experiences even if not directly applicable. I like being better prepared for the future as you never know what’s next.


On my older aids I had the back-out problem. I think it was caused by the wires being a little short. My newer (*but still old KS7’s) have longer wires and they stay in. (I have closed domes.)

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The wire length isn’t my issue, my left ear mold/ITE aids have always slipped the slightest amount with even moving my jaw, or bumping my earlobe. When I look at the ear molds/ITE aids I believe it has to do with the shape of my ear canal. My right ear mold/ITE aids have never be an issue.