Occlusion

Hearing Aids
#1

I’ve had Trax 42 for 10 months now. Started with double domes, they kept backing out of my ears. Put locks on still backed out. Went with molds, no locks they backed out. Now have molds with locks and it solved the problem.

BUT…I battled a fitting issue, they made my ears sore, and since it’s 120 miles one way to Costco, I started filing on the lock portion of the molds. Hurting my ears to the point I couldn’t wear them. I have solved it, they are pretty comfortable now.

I immediately noticed occlusion with these molds with locks. The HIS said as I recall I had the largest vent. I have not been addressing the occlusion because I wanted to get the other issues under control. I’ve also noticed the ‘speech’ clarity with these are not as good as previous molds or double domes…but the issues of having to always push them into my ear…I ain’t going back there. I had the largest double dome they made BTW.

The notice of occlusion is mainly I feel I have a stuffed up nose. Take the aids out, it goes away. I’m in the process of setting up another trip to Costco…what/how should this occlusion be addressed?

#2

In trying molds, where the silicon (soft) molds tried? If not, that might be a option.

#3

I had trouble with occlusion with the double domes. I had Rexton click lock soft silicone molds that have locks and 1.6 mm vents made that solved the occlusion and are extremely comfortable to wear. Costco gave me some some fuzzy little strings to run through the vents to keep them open. Did they make any program changes after the new molds?

#4

Yes I’m sure they did, because I immediately knew there was a problem. The molds was shorten by the HIS as the initial alteration, and it made quite a bit of difference. How big can a vent go without destroying the effect of the aid?

— Updated —

Yes I’m sure they did, because I immediately knew there was a problem. The molds was shorten by the HIS as the initial alteration, and it made quite a bit of difference. How big can a vent go without destroying the effect of the aid?

#5

I think the max vent size is determined by your hearing loss. In my case it was 1.6mm and in the end my right mold had to have a small sleeve put in it to make it slightly smaller to eliminate feedback. They also offer a option called a select a vent that is larger and is supplied with different size inserts to customize it for your hearing loss. If the molds do not fit right I would have them remade until they are comfortable. My soft molds did not require any program change when I switched from double domes to them and the pressure was relieved instantly. There should be zero pain from the molds if they are properly made.

#6

Yes realize that. If it wasn’t 120 miles one way, I might have done that. But I’ve got them comfortably now, and they are staying put. I just need the occlusion improved a bit. Waiting to hear from HIS person now, after sending email.

— Updated —

Yes realize that. If it wasn’t 120 miles one way, I might have done that. But I’ve got them comfortably now, and they are staying put. I just need the occlusion improved a bit. Waiting to hear from HIS person now, after sending email.

#7

Try to plug up the vent in your mold with a putty and see how much more occlusion to feel, if not much different, the venting is not done properly. Maybe the opening end of the vent is against your canal wall and is blocked. If there is a significant difference, see if you can make the vent larger, that will reduce the occlusion effect. The fitting of the ear mold is very important in your case as you need a very tight (but comfortable) fit mold. Ideally with soft material and very small vent and of course you can wear it for 10 hours a day without pain.

Be aware, if you make the vent bigger, you will not have as good clarity, because there will be feedback issue. Your hearing loss required a lot of high Hz gain, those will leak out from the vent and cause the hearing aid to squeal. To eliminate that your reduce the high Hz gain and there goes your clarity for speech.

So, try to get use to the occlusion (its just a matter of time and perseverance). Assuming you are quite handy with fiddling small things. Get a hard mold with select a vent where you can alter the size of the vent by changing the sleeves. Get the audi/HIS to set up manual programs with different levels of high Hz gain, each manual program for a different venting sleeve size. Check the feedback level at each manual program by loosely covering your ear, you should hear just a little bit of squealing. Once you have that set, you start with the largest opening sleeve and program with least high Hz gain, and gradually move it up until you can use a mold with minimal venting and most high Hz gain.

Also, you can safely cut off the gain at 6000 Hz to help with the feedback control.

CL

#8

So the receiver isn’t going to resonate at 2.5-3Khz where it’s designed to compliment your natural canal resonance, but at 6KHz - interesting…

#9

you are right, they will resonate at all Hz, not just 6 & above. the hearing aid is trying to amplify sound at all Hz, the limit of how much it can amplify depends on the limit of the receiver/speaker, it ALSO depends on how loud it make before the resonance happen. Hopefully its loud enough so that you can hear it before that happen.

Your hearing loss at 6k is too high for any hearing aid to produce enough loudness for you to hear it. The ‘s’ and ‘th’ sound is at 6k. If you have a chance to trial a hearing aid, ask the audi to make the ‘s’ sound with your hearing aid on your ears, don’t look at the audi while you do this test. See if you can hear it. Now ask the audi to cut off 6k & above AND SHIFT/COMPRESS/TRANSPOSE that range of sound to a lower Hz that you have less hearing loss and see if you can hear it. May not sound like and ‘s’ but you should hear some sound.

Assuming the range of Hz above 6k will not be audible to you at any reasonable loudness produced by the hearing aid. it is better to cut it off as that’s the range of Hz that causes feedback/resonance problem most. Now you may not hear that resonance, but the people around you will. CL

#10

You’re missing the point: receivers hit saturation sooner at 2.6Hz than elsewhere by design - feedback will usually occur at this point in the main or double/half harmonics.

I don’t have a loss - assuming that people can’t hear above 6Khz is a bit short sighted in terms of the broader band receivers now available on the market. Transposition/shifting is meaningless for people with flat losses too.

For the record parts of the S/TH sound occurs around 6Khz, but lots of it occurs elsewhere as well - take a look at a live REM if you want to see where.

#11

Feedback or feedback loop is caused by the hearing aid picking you it own sound and re-amplify making the same sound louder than before. This got picked up again and re-amplify… until the speaker can no longer make it louder and saturate at some particular frequency.

Resonance has to do with the acoustic properties of your pinna, ear canal, ear drum and the receiver of hearing aid. This also has to do with the wavelength of the sound and the dimension of you ear canal. Lower Hz had longer wavelength that is longer the your ear canal and will not cause resonance. Higher Hz has shorter wavelength and cause resonance in you ear.

The issue here is the feedback loop, because it cause saturation of the receiver that distort ALL the sound from the receiver.

Shift/Compression/Transpose of Hz may (or may not) work for you. You have to try it at different setting AND it will sound different. There will be a learning curve. Of course its the best if you don’t need that and can hear the s/th after the hearing aid amplified it, but I doubt.

A spectrogram will show you more information of frequency & intensity of sound over time. If you can’t hear above 6k Hz, what difference does it make if I cut it off or not. You still hear the lower Hz. Most of the energy from the s/th sound is around 6k, if the hearing aid can move that to a lower, more audible Hz, you brain may be able to relearn that and map it to s/th after some training. CL

— Updated —

Feedback or feedback loop is caused by the hearing aid picking you it own sound and re-amplify making the same sound louder than before. This got picked up again and re-amplify… until the speaker can no longer make it louder and saturate at some particular frequency.

Resonance has to do with the acoustic properties of your pinna, ear canal, ear drum and the receiver of hearing aid. This also has to do with the wavelength of the sound and the dimension of you ear canal. Lower Hz had longer wavelength that is longer the your ear canal and will not cause resonance. Higher Hz has shorter wavelength and cause resonance in you ear.

The issue here is the feedback loop, because it cause saturation of the receiver that distort ALL the sound from the receiver.

Shift/Compression/Transpose of Hz may (or may not) work for you. You have to try it at different setting AND it will sound different. There will be a learning curve. Of course its the best if you don’t need that and can hear the s/th after the hearing aid amplified it, but I doubt.

A spectrogram will show you more information of frequency & intensity of sound over time. If you can’t hear above 6k Hz, what difference does it make if I cut it off or not. You still hear the lower Hz. Most of the energy from the s/th sound is around 6k, if the hearing aid can move that to a lower, more audible Hz, you brain may be able to relearn that and map it to s/th after some training. CL