Open dome vs. OpenBass dome

(N.B. I recently posted the following comment in the midst of another thread, but I’m hoping that it will receive more responses as a separate thread.)

The Philips 9030 and Oticon More can both use an OpenBass dome (although I’m not sure if the domes are interchangeable.)

The “white paper” for the Philips 9030 says this about the OpenBass dome:

The new dome, called the OpenBass dome, replaces the current Open dome… In the legacy Open dome, the acoustical venting is realized by “flat” holes that are perforated on the surface of the silicon dome. In the new OpenBass dome, the acoustical venting is realized by 3D grooves through the silicon dome that are formed by a curved floor, and a ceiling towards the base of the dome. This structure is three dimensional, as opposed to flat holes in the legacy Open dome, and it is referred to as SoundTunnelsTM.

Compared to the legacy Open dome, the benefit of the SoundTunnelsTM is that engineers were able to reduce the acoustical venting area of the OpenBass dome by 70 %, while maintaining the same “openness” perception. The combination of a reduction in venting area and a higher predictability of the effective venting once inserted in individual ear canals has several benefits, including that it creates a better acoustical environment for the feedback canceller, which also facilitates the match of the prescribed gain on expected target gain values.

My question: Does the OpenBass dome create more “insertion loss” than the standard Open dome? The above description is a little confusing. If the acoustical venting area of the OpenBass dome is reduced by 70%, how can the same “openness” perception happen?

Do any Oticon More or Philips 9030 users here have experience with the differences between the two domes?

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I’m using the Oticon open bass domes on my phonak paradise 70 hearing aids. Prior to that, I tried various different phonak open domes and a few closed domes.

They’ve been amazing for me. It’s resolved my issues with hearing soft talking lower men’s voices in person and via the TV stream. Plus music via Bluetooth has all the bass notes again. .

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The OpenBass dome is supposed to help with low frequency loss, so I just requested them from Costco. It’s going to be a couple of weeks until they arrive and I’ll be comparing them with the double vented open dome for the Philips 9030 so I don’t know if my observations will help but I’ll post them f I experience a difference.

I’m particularly interested in the engineers saying this reduced venting design doesn’t cause occlusion. That’s always been a problem for me without venting.

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What “problem” are you trying to solve? It looks like you have excellent low frequency hearing and open domes will let you take advantage of that. Your high frequency loss is mild to moderate so open domes should allow enough gain to the high frequencies and not generate feedback. I would expect the Open Bass dome would allow more gain at high frequencies without generating feedback, but you likely don’t need it. If you needed more gain at low frequencies, it could prevent it from leaking out as badly as open domes do. If you want to try the Open Bass domes, feel free, but I don’t think anybody elses experience are going to help you much, even if they had your exact audiogram (People are different) Thanks for having posted audiogram. It really helps put things in context.

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These domes are not for your hearing loss. What do you experience when you experience “occlusion”? Occlusion is not impossible with the hearing loss you have posted, but it’s rare-ish. Do you get it when you plug your ears with your fingers?

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MDB, thanks for your thoughtful reply. At the moment, my question about whether the OpenBass dome is more occlusive than the Open dome is somewhat academic (“Inquiring minds want to know…!”). I use the previous generation of Philips, the 9010. I currently have open domes, and am generally happy with them. I understand that the Philips OpenBass dome can not be used on the 9010, only the 9030.

I do have a slight issue with feedback, however. Being a musician, I can’t tolerate what the hearing aid feedback manager often does to steady tones (producing a vibrato effect). I have the feedback manager turned off on all four of my hearing aid programs. Consequently, I get some feedback when I cup my hands to my ears, or if I’m lounging on a recliner, and the hearing aids come close to the headrest. It’s not awful, but does limit some of the high frequency gain that I can use before feedback isn’t tolerable.

I’m also looking ahead to the near future, when a new model of the Philips should be introduced at Costco (9050?), which I’ll consider purchasing due to technical advancements. As you mention, the OpenBass dome will allow me to have more high frequency gain available without feedback. However, I currently have good low frequency hearing, and if the OpenBass dome itself creates noticeable insertion loss of low frequencies, that would not make me happy. The section from the Philips white paper that I quoted in my original post is confusing: How can the same sense of “openness” of an Open dome be achieved by the OpenBass dome that has 70% less acoustical venting?

I probably won’t know the answer to my questions until I try the new Philips model when it is available. But in the meantime, if anyone has experience with the OpenBass dome vs. the Open dome, I’d be interested in their thoughts. Thanks.

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Have you tried having the feedback management program turned on in just your main program? (not music) Regarding how the Open Bass Dome could have the same sense of “openness” with less venting? Psychoacoustics is strange stuff. Our perceptions often do not make sense.

I’ve never tried that so I took out my aids and stuck my fingers in my ears. Answer is no.

What I experience that I call occlusion is that closed in and muffled feeling. It’s almost physical, like very narrow walls around my head. It can be anxiety producing and so impossible to ignore that I have to focus intently on what/who I’m listening to and keep trying to push it away–so distracting.

With the custom molds I’ve worn for nearly 30 years, that tends not to happen. They have a hole in them underneath where the speaker fits in. The problem came up again as I’ve been trialling new aids and trying to figure out how to keep from being overwhelmed by background noise. My existing molds don’t fit the Philips receivers so I’m using a generic mold for the first time.

I thought these OpenBass domes might be useful because they help with low frequency loss. Those voices are the ones that are toughest for me to hear when the person is also soft-spoken. If they would, then the fact that these domes are not occlusive is a side benefit that I thought might make them wearable for me. Why do you think they’re not for my type of hearing loss?

Added: I just looked up the definition of occlusion online: “The occlusion effect is the sensation of increased loudness (sound pressure level), especially in the low frequencies, a person experiences to self-generated sounds (vocalization, chewing, swallowing, walking, and the like), when the ears are covered (occluded).” HearingReview.com Then I put my fingers in my ears again and talked–my voice sounds louder but muffled. Then I ate a cracker and put my fingers in my ears while chewing. Loud. Then while walking in sock feet–I hear my footsteps pounding the floor when usually I don’t hear them at all. If I just cover my ears with my palms and talk, my voice sounds louder than when my hands aren’t over my ears.

Custom mold with a 2mm vent is good.

The trouble with open domes (open bass dome is an open dome) is that you likely won’t be getting sufficient gain to support your hearing loss at 1 kHz and under. Closed in muffled feeling can be caused by under amplification in the lows, although loud self-generated sounds when you stick your fingers in your ears is certainly occlusion. You want enough venting to make those sounds tolerable, but not so much that the lows just leak right out of your ears.

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Thank you for this advice and information. After 3 days with these aids and domes, I thought I’d try the Bass and if that made no difference get custom molds made. Today, working in the yard, one of the aids fell out of my ear. That’s never happened with custom molds, so another reason to go that route. Many thanks!

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Moving to the open bass domes has been an absolute game changer for me.

Bass notes while playing my guitar are great. Bass notes and drum sounds while streaming music are back.

I’m no longer struggling to hear lower soft talking people.

Closed domes were a nightmare for me personally. They’d slip out of my ears even with the retention pcs. It’d be even worse while sweating.

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Can someone provide a specific link to Oticon “open base domes”?

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So, if I’m reading this chart correctly, an Open dome is not even a possibility for the Oticon More? Hmm… raises even more questions as to what an OpenBass dome actually does compared to an Open dome!

Well it’s not impossible to interchange the two (Open Dome, OpenBass Dome). That is, the miniFit receivers have not changed, therefore you can still physically interchange the two domes because both will still fit onto the unchanged miniFit receivers.

However, during fitting (Selection/Acoustics) the Earpiece pulldown menu selection will be different depending on which instrument is being fitted (Opn or More);

  • More = OpenBass Dome
  • Opn = Open Dome

So while it is physically possible you would end up with the wrong acoustics setting so don’t do it. If that makes sense?

The gentleman I bought my aids (a German audiologist) had me use micromolds(I use single vent base domes) in the drop down to achieve a greater range of available adjustments. That was with the More 1 aids, when I tried that with phonak P50R the results were dismal sounding.

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I am looking to improve the sound of streaming music from my iPhone to my Oticon Opn S aids. I was using double vent closed domes 6mm, but the music sounded so much better when I plugged my ears with my fingers. I can’t walk around with my fingers in my ears, so I tried open domes 6mm. Overall, as ambient sounds and speech are better but the music streaming is the same. It’s much better with my fingers in my ears. I’m stumped as to why this is and what to do next to get full enjoyment from streaming music. Any suggestions? TIA - Jim

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For best streaming, you need to close of the ear canal. If you’re going with domes, something like this should do it: https://www.amazon.com/Hearing-Double-Silicone-Washable-Earplug/dp/B09WZC3MN7/ref=asc_df_B09WZC3MN7/?tag=hyprod-20&linkCode=df0&hvadid=632050264455&hvpos=&hvnetw=g&hvrand=15991540310459308929&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031839&hvtargid=pla-1880419333561&psc=1

You may need to try various sizes and you may need to trim a bit. With the right size, you should be able to approximate fingers in ear. Other possibility is that your receiver wires are on the short side and don’t let your domes fully seat. Another option is custom molds.

Ok Thanks…!! I’ll try that.

It’s amazing…the right dome makes such a huge improvement.

I thought I was doing ok and plugged my ears and sound was so much better. My current audiologist is amazing. He gives me domes he thnks I need; then he adds a pair or so that are larger. I’m using the larger ones now.

I look at them and wonder how something so cheap to make can make such a difference!

(That’s the engineer in me. :wink:

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