Feedback when using open domes despite audiogram saying open domes can work

My friend has finally (18 months process) has some NHS Nathos Auto Micro (Bolero V70 M) with open domes.

He’s finding there’s a lot of feedback with the open domes so I had a look at his fitting as I’ve got all the equipment.

He’s using large open domes and his audiogram fits the open domes range but the feedback test is massively reducing his gain in the higher frequencies.

Is there anything I can do to stop the feedback test reducing the highs so much?

The software is also recommending open domes.

From my experience and the experience of my fitter, that’s a downside of Phonak’s feedback test. A couple of ways to “cheat” the test. 1) run it while plugging one’s ears with one’s fingers or 2) run it with a more occlusive dome. (and then switch back to open) We tried both and it had very similar effect. I’m going to try custom molds. Good luck and let us know how it goes.
And to add: Just because the software recommends open domes, it’f fine to try something different. Software recommends open dome in one ear and vented in the other. I wear vented in both. If I tried open in my left ear (as recommended by software), I’d give up a heck of a lot of the highs. Another possible option is to not run the feedback test, but it often still wants to cut out a lot of the highs.

What was the effect? More feedback or?

The effect is letting Target deliver more gain to the high frequencies. This has resulted in somewhat more feedback, but certainly tolerable.

As an experiment try looking at the gains to see what they do when switching acoustics. You will see gains increase as you use more occluded acoustics and gains decrease with more open acoustics. My thoughts are Target can recommend more than one type dome for example.

Knowing this if your friend is not hearing highs as needed with open domes a more occluded dome is needed which will allow the aids to increase the gains for these highs without feedback.

It’s all about hearing. Using the correct aids or receivers for a loss and picking out the correct acoustics that are needed to get that gain without feedback. Then comes the tuning.

I’m only seeing open domes with a weird type star next to it. Closed or power domes are not recommended.

Thanks. Will give it a try once he’s next over mind. The weird thing is, he’s no where near the limit of the HAs so I was surprised it feedback so much.

I think manufacturers have a jaded opinion of people with high frequency losses. They got tired of all the complaints of loud noises and hearing aids sounding tinny that they often don’t attempt to supply full prescription gain to the high frequencies. I’ve seen similar feelings toward frequency lowering of not wanting to set it to adequate levels.

He popped over last night.

We’ve solved the issue. I put his HAs on to my ear mould for my left ear. Ran the feedback test with the HAs in my left ear.

Then selected ear moulds and not slim tubes within the software and selected open ear mould.

If we select slim tubes and open domes again, he starts to get feedback but selecting open ear mould, it seems to solve the feedback issue.

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Awesome!

When you say feedback issue, do you mean constant squeaking or only when you put hands close?

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It wouldn’t stop squealing unless he put his fingers in his ears.

Uf. That’s bad.

I think I’ve misunderstood what ‘having feedback issues’ can mean. Thanks for confirming how wrong I was.

In my experience that’s ‘they squeek if I place hand over ears’ or someone kiss me at the cheek.
Having mold with vent was enough to not have any issues when getting kisses.

I’m trying to figure out if I can get kisses with open dome without squeak in the ear.

But I think I approached the purpose of feedback control all wrong :rofl: