So after really struggling with my HAs in closed domes. I changed to open domes. Even though I could hear much better, there is still some range of frequency which I cannot process.
Latest thing I tried is one HA with closed (for low frequency ranges) and the other open (for high frequency). I try to switch between them every week.
Although it worked good for me, I still has concerns that HA is programmed for open. and I am not getting much benefit until I reprogram it. Which I cannot do because I keep switching.
I switch between them because I am afraid that wearing closed domes for so long will affect my ability to hear high frequency in that ear with closed domes (at the end of the day when I remove the HA I feel like my ear cannot hear well and need time to readapt) . Any feedback on my approach. Thanks
Your sensation of not hearing high frequencies after taking out your aids with closed domes is just that, a sensation. I think this happens to most everyone who wears hearing aids.
To not wear aids you are actually working very hard to hear, stressful but you do hear some. When you do wear your aids you are not working as hard to hear, less stressful. Then when you take the aids out you sense less ability to hear because you are not working hard to hear at that point.
I am not a professional, but I have been down the road of open, closed, and now custom vented molds. It is my understanding that venting or closing down has two basic considerations.
One is that if your hearing is poor in the low frequencies, your hearing aid receiver may not have enough power to build up the low frequency pressure needed to boost lows. Your low loss is not real bad, but your left ear probably does benefit from a more closed vent. You may lose bass without at least a partially closed vent.
The second issue is feedback. Having a significant hearing loss in the 3 kHz range means you will need significant gain at that frequency. That is where feedback is most likely. Your loss at 3 kHz is getting up there, and I suspect there is feedback potential. A more closed vent would help prevent feedback. Or it would allow for more gain to bring you up to target, if gain has been reduced to prevent feedback – something that is not uncommon.
What brand of hearing aids do you have? The reason I ask is that Rexton/Signia/KS8 aids have a click sleeve that is described as closed. However it is not closed, and has one small vent that is equivalent to a 1.6 mm vent. That is probably in the range that you need. I used them for a while and found them quite comfortable.
If you want I can run some Connexx software that I have which will recommend a vent size, and it would give you some idea of where you stand for vent requirements.
Edit: The other benefit of more closed venting is that it lets the hearing aid control noise better. A hearing aid cannot supply negative gain. It can just reduce output. However, with a closed fitting this is like a negative gain as the closed fitting is acting like an ear plug for noise. It can also help with directionality as the hearing aid can decide which direction you hear from, and shield you from the other directions.
No, I do not. Your low frequency hearing is good enough to use open domes. You could get by like that for a long time possibly, I did.
Using tulip, closed or power domes will improve your hearing aids ability to function without feedback and give a more balanced sound across all frequencies once adjusted properly for you.
Not an expert, just passing some things on I have learned.
Thanks Sierra for your informative reply,
Yes you are right, I do feel bass is blocked with the closed doom. But as you said it’s beneficial in noisy environment (that is why I am going with open and closed).
Although I have some feedback only when something come close to my ear. It doesn’t bother me much because usually it is temporary unless I am standing next to a wall or a board for a long time.
I am having Widex Beyond now. Although my past Oticon was having something like click sleeves. I didn’t benefit much from them.
I guess I can visit my professional again and discuss. Maybe adjust for the low bass in the closed one…
Glade you are not candidate for open fit your 1k loss is significant and where most of power of speech is present you should use closed fitting if possible occluded.
I see that Widex have a few different Instant Ear-Tips. They have some round ones with one and two vents, as well as some Tulip ones. They might be suitable for your loss while giving you some bass back.
This is what the Connexx software (Rexton/Signia) shows with open domes. It is right on the edge of lots of feedback potential (red and blue shaded areas), and it is suppressing gain in the 2-4 kHz range to avoid them.
Here is what it shows with custom molds. It allows for more gain to address your loss and avoids the feedback areas. It shows a 2 mm vent in the right, and a 1.6 mm vent in the left.
You can put different domes in each ear but the program should be updated to compensate for them. In your case both ears need a semi closed and they are really not that different.
I never knew that HA actually suppress gain to avoid feedback.This now makes sense on why sound is much better in the closed domes. I believe I will reprogram them to adjust for my setup as open in the left and closed in the right. Thanks for your insightful comment.
Hearing aids primarily use a notch filter that attenuates the offending frequency when feedback is detected, or they shift the frequency of the offending frequency by 25 Hz or so. That prevents the feedback from building up.
Separate from that when the hearing aid is fitted they can do a critical gain test that determines how much gain can be achieved without getting feedback. In the software used for my hearing aids (KS8 - Signia, Rexton), they can save that critical gain data, or not. If they save it, the programming software reduces gain in the offending frequency area. That was with Connexx 8.5. Now I am running the 9.0 version of the software, and my observations is that it automatically reduces gain to avoid the feedback areas when it derives the prescription formula.
In any case, a common “cure” for feedback is for the fitter to reduce your gain manually in the likely frequency areas, until you stop complaining about it… So, that means if you do not get the best fitting venting for your loss your correction gain can be limited by feedback.
Too bad my HA professional is incompetent. Just fitting, no speech intelligibility, no REM, no nothing. I have so many question but none get answered. I can’t wait until I get Widex remote care enabled in my county so I will never have to visit there again. Thank you again for your informative replies. Maybe I will join the self programing workforce
Hey, if you paid thousands of dollars and your audi isn’t using standard-of-care procedures and tools, they are STEALING money from you. Return the aids if you have a trial period and go to a professional audiologist who will serve you as they should.
Self-program if you have skill and understanding in audio physics and electronics, and if you have the genuine interest. But you’ll never afford REM equipment, so you’ll end up in the same boat, probably. Self-programming is mainly for ease of fine-tuning. The basics still should be done by a professional, with professional equipment and procedures.
Hi Haggis, Thanks for your comment. I have an electrical degree but never found the time to start investigating sound processing realm.
Yes I get that DIY will not give satisfactory results without expensive tools. And I am thinking of raising a compliant against HA center.
Could you point me where I could find some information about what a proper fitting test is so I know what to ask for? Thanks again
With new aids the fitter should program them based on your measured hearing loss, and according to a prescription formula. Picking the right prescription formula is probably the first critical decision. The most common standard one is NAL-NL2, but there are others like the DSL v5, and most manufacturers will have their own proprietary formula. The formula may have different levels of acclimatization. The formula adjusts to the selected fitting style used; open, closed, or semi open, or in the case of a custom mold, the specific vent size.
Next it is best to have a critical gain test done, or feedback test. This evaluates the potential for feedback. The software may consider this automatically or the fitter may take note and make adjustments manually based on the potential and your experience with the aid.
After that they do the Real Ear Measurement to verify that the sound levels identified by the formula are actually achieved in the ear canal.
After that fine tuning may be done based on what you hear.
My understanding is that acoustic changes do require a new REM.
The change of a vent, mold or dome type could affect the receiver output at the eardrum.
Running the feedback manager is also a good idea when acoustics are changed.
