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Trench venting

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Edited

Anyone have any experience with the pros and cons of trench venting? I wondering about trying it to stay with titanium. Phonak in the US will not make titanium cavity slim tips with any venting (Activent only). My cShells are what Phonak calls “Semi-IROS D-shaped” at page 18 in Customspedia (https://www.phonakpro.com/content/dam/phonakpro/gc_hq/en/campaigns/ite-excellence/documents/PH_ReferenceGuide_CustomProducts_210x297_EN_027-0670-02.pdf16). I’m wondering about trying the “Styled semi-IROS-trench”? I’m also curious about “Styled inverse IROS”? This is for a cookie bite loss.

This article does not seem to address the trench design (think that is different from notch) but may interest some: https://www.tandfonline.com/doi/full/10.1080/14992027.2022.20399661

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Yes, but they don’t offer a titanium slim tip with a hole as a vent. My audiologist said she didn’t think activent would work well for me. I’m not sure whether that is correct but it could be? They were sent back before I could try them.

Without your in your profile, it is harder to give you advice. (If you’ve put your audiogram in a post, I don’t remember it.) Here3 is a fitting guide. If your hearing is much worse, it may not be strong enough for your loss. A few folk with technically worse hearing still wear and like them. Note they only last about 6 months before needing replacement. Some decline the option when they discover the cost.

Best wishes,
WH

Edited

In reply to @WhiteHat

I’m borderline on the fitting guide but that is not the issue. The audiologist doesn’t think the fully closed position will work for me and questions whether the open position is right as well. It’s similar to an open dome. Apparently someone she consulted agreed and so I’ve got cShells for now.

Edited

In reply to @Neville

I know. The audiologist tried to order a titanium slim tip with vent thinking it would come with a non-activevent receiver not realizing that Phonak doesn’t offer that. Phonak does not offer any cavity mold option in titanium other than the no physical vent option with activevent. Hence the question about trench venting generally and versus the cShell configuration I have now.

To greatly reduce occlusion effect, it would be good to make cShell from very deep impression, at least 5mm past 2nd bend of ear canal. Earmold/cShell from that will reach the bony part of ear canal, which can reduce occlusion effect even to zero.

I have 0.9mm vent and relatively good LF hearing and I have no problem with occlusion effect, even considered cShell with no vent.

Sometimes someone has too small ear canal for this solution.

@Bimodal_user said:

cShell from very deep impression, at least 5mm past 2nd bend of ear canal

The impression is deep but how can I determine whether the cShell reaches the bony part of the canal? One cShell seems to hit something and bottom out in my ear. I barely have to touch the mold for it to tap that sensitive spot. No idea whether that means they are deep. They are deeper than the Virto R I tried. They are deeper than other molds I have.

I don’t think my issue is occlusion but I’m not sure. You seem to tolerate the aids processing most of the sound and/or are not bothered by low frequency issues.

@user490 said:

how can I determine whether the cShell reaches the bony part of the canal?

It is not necessary to assess that anatomically. You should have these things:

  1. Feedback threshold which let you achieve proper gain, especially in high frequencies.
  2. Have vent closed enough to get necessary low freq. gain
  3. Occlusion effect as low, as reasonably possible without impacting audibility and clarity negatively.

If you have them deeper than Virto, perhaps it’s quite possible, they’re deep.

It’s not only about occlusion. There’s a full feeling which I think may be called internal pressure. There’s also what might be called drumhead effect. Some fit issues. Probably some other things happening too which are not easy to describe. Overall it seems like a different mold would be better but I’m not sure where to go with Phonak options. I want to give a titanium option at least one more try. Then I may have to switch to acrylic slim tips with a vent.

No, manufacturer usually doesn’t share acoustic mass of individual vent. You can also consider ampclusion vs. occlusion effect. The latter is existing also when is turned off.

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