There are some generalizations; however, they are rules of thumb, nothing engraved in stone.
Your audiologist should have said rather "there is a higher risk of occlusion effect, but it is not 100%."It is untrue to state definitively, “you will have an occlusion effect with eaarmolds.”
I am rather extreme case of not feeling occlusion at all.
Yes, with eamold there is many option with different length or (more important) diameter of vents.
The bigger the risk of occlusion effect, the wider vent shold be (in general).
I don’t know, it any other way to check different diameters (maybe Select-A-Vent SAV? Unaccessible in my place).
For me, it was trial and error (and much cash spent, around ~$100 per earmold) because Target software always proposed 2.2–3 mm, and without my requests, I would get vents that large—even 3 mm or larger (my last unwatched earmold).
I think it was worth the effort because I have an earmold that allows me to use the full potential of the receiver due to a maximized feedback threshold. I have a 1 mm diameter for my Paradise 90-RT.
My 3 cents only, but I thing your audiologist may explain that in better way. Did she show you the feedback thresholds and limitations they impose?
I have a similar loss like yours. I started off with domes and was hesistant to try molds because I was afraid of occlusion. I now have canal tip molds made of thermotec material with 1.4 mm vents and do not experience any occlusion and feed back has much improved. So I would say it‘s worth a try……
My audiologist has only shown skepticism, so far. Assuming I go forward with earmolds… presumably I can sit down, go through the trade-offs, and get a proposal from her.
At least in your case, you were able to get down to 1mm without experiencing “occlusion effects”, huh. So then that allowed you to get 40dbs or more amplification/“insertion gain” at the various frequencies (at least based on the estimated feedback thresholds on slide 25 of the venting presentation). Do you have notable low frequency hearing loss, tho?
Do you consider a sound quality test with your fingers stuck in your ears at all worthwhile?
Thanks…that’s informative & reassuring. And I was wondering if canal tips (said to be for mild to moderate hearing loss) were appropriate for me, so you read my mind!
Canal tips were the only option for me because I wanted the molds to be invisible. I clearly hear better with the molds than before with the vented domes. I can also highly recommend thermotec material - the molds fit very nicely and do not cause any itching - I have them in my ears for up to 16 hours per day.
See my audiogram. Simply speaking - no until 500 Hz. I can even have 0.6 mm. Left ear is completely deaf.
But when? Without HA? Then if I press the tragus lightly to seal the ear canal, then there definitely is an occlusion effect (checked by saying “ee”, “oo”, “ah”).
When I press the tragus harder (still keeping the seal) - there is no occlusion effect. Zero. It’s probably because I press the soft tissue to the bony part of ear canal.
I did realize I had access to your hearing profile right after my last reply
The “test” would be to see if sound improves with your hearing aids in and fingers blocking the ear opening. Supposedly that simulates having molds in your ear. I’m skeptical, but thought I’d ask.
I already have earmold, almost never domes (only power double domes used for 3 weeks during waiting for last cShell), so the finger method didn’t work. Even if I had domes, the proposed test isn’t credible without necessary adjustments of gains.
same for both ears. this was my audi‘s suggestion - he said that was just at the border between closed and open fitting - after I had told him that I liked the molds, he was kind of relieved and told me that there was a 50% chance that I would like these molds. I liked them and will keep them…
I’ve been using music streaming (from a Samsung phone as required by Widex Moment) & ‘Widex TV Play’ for 2 or 3 weeks…
-Music sound has been quite good.
-TV sound stream has been inconsistent. I may be experiencing periodic connection imperfections, in addition to the inconsistent sound quality between various TV productions. Does anyone have experience with the ‘Widex TV Play’ accessory?
I have an upcoming appointment to receive my earmolds. [Widex made them based on molds my audiologist did from my ears. Widex sized venting based on my audiogram ] Presumably the venting will be too large, based on your experience. I am allowed 90 days for venting adjustments @ no additional cost, anyway.
Finally we’ll be trying to optimize the amplification gain, again. I’ll be reviewing the slides you referred me to again, and may have a question or 2.
I got my earmolds (Widex had adjusted me back to 100% of prescription & sized the vent to 2mm) and my audi ran Widex’ feedback management & REM programs. My sound experience was much better with sound from speakers. Streaming is even better, of course. Occlusion effect is minimal & sporadic (see below).
My audi was happy with the graph on her screen which showed REMs right on the programmed targets thru 4k hz, and somewhat above. She claimed to be “on target” at 6k, which she had previously achieved only with Oticon. I asked what amplification (ie. “insertion gain”) I’m getting across the frequencies “for my money”. She said that’s not reported by the manufacturer’s programs and would have to be manually calculated.
I do have a fit problem with my right earmold. I experience discomfort based on time inserted and facial movements (eg. chewing, teeth brushing, pronounced facial expression). In addition to the discomfort that builds over the course of the day, occlusion does occur on occasion resulting from exact mold positioning & facial movements (this occurred with the unvented, rubber tips, too.)
I’ll be seeing the audi to get the right mold issue addressed and to find out the “insertion gain” I’m getting, next week.
Great to see improvements! It seems that there was indeed a comb effect with the domes.
It seems she measured REAR for quiet, moderate and loud speech, and perhaps REAR 85/90 to measure MPO.
To get REIG (Real Ear Insertion Gain) she have to measure REUR (Real Ear Unaided Response). This is measured with no hearing aid. Then software should calculate:
REIG = REAR - REUG
Out of curiosity (possibly paid additionally) you can have measure REOG (occluded gain; after the turned off HA is put on the ear) for assessing the vent and earplug effects of your new cShells. It provides some useful information, regarding e.g. comb effect.
Occlusion is when you try to say ‘ee’ or ‘oo’ and it is unnaturally loud, or when you chew something hard, like nuts, it is also loud. The earmold may slip out of the ear canal slightly and you may feel occlusion.
Regarding discomfort - sometimes it is necessary to get used to it, but it shouldn’t be painful. Give it a chance before making a new (possibly deep) cast. And if it is to be remade, ask for the impression to be taken with the jaw open (approx. 2.5 cm of mouth open) during the curation of the silicone.
Unfortunately, not yet. I returned the previous titanium earmolds on 11 April and the new ones will be in about a week.Titanium seems to take longer to make.
I’ve learned many new things after reading this thread. When I saw his audiogram, I would have thought that a simple, low end HA with good programming/REM and open domes would work because his hearing loss is not that bad (According to WHO, his hearing loss is mild/slight) and it is good at low frequency. I’m wondering if the audiologist was too aggressive and made the changes too quickly and the patient did not adapt. Very glad to see things are improving (and demonstrate me that an audiogram is not necessarily an indicator of how easy the fix can be)
Probably not. IIRC, the OP was even underfit, at least in high frequencies, which were out of target…
It is a rule of thumb, “first idea,” but not necessarily the most optimal for the some patients, especially if we consider not only the comb effect but also the effectiveness of directionality, noise reduction, etc.
An audiogram is only one part of a patient’s hearing “picture”; it’s not perfect, but quite repeatable and useful. There are also ear anatomy characteristics, fitting algorithms, cochlear dead regions, etc.
My take from a layman’s perspective is that my audi did reduce amplification (of about 3k & up) too quickly. It wasn’t until the past week that she gave me the full prescription (and I’m dealing quite well with some unusually loud sounds, as Bimodal chastised me to do early on in the thread )
My guess is that earmolds are helpful due to a fairly significant pocket I have well down in my left ear canal. As for the remaining mold fit issue, I’ll guess that my jaw is still off a bit from an auto accident 40+ years ago in which my chin came down on the top of the steering wheel. It puts a bit of pressure out toward the ear lobe, particularly during facial movements. Just guesses, but I’m the man living with those idiosyncrasies (and the pros don’t always want to listen to such detail).
It’s quite possible, because when the difference of 3k Hz and up is less than 10 dB between amplified and “through vent/leaks” sound, the risk of comb filtering is increased. There was also a risk of imbalance between medium- and high-frequency sounds, causing sibilance.
As you can see in the last slide, “flutter” occurs when the vent and amplified path interact if there is a small decibel difference.
Oh there, there he was “chastising” there It was just an insight.
So with domes it was quite possible that you has high risk of acoustic feedback with more amplification of higher frequencies (and low feedback threshold).
The effect of that ‘pocket’ probably can be measured by REUG/REUR (more). REOG can A BIT show how the earmold with vent (without HA amplification) deal with it.
This was a quite probable indication for a custom earmold, not universal solutions like domes. Put your finger about 1 cm deep into the ear canal and try to feel the movement of the head of the temporomandibular joint.
Audiologists have many tough calls to make. Faced with a patient complaint about too much treble, sounds like a cheap transistor radio, etc, does one risk alienating the patient if they tell them to just give it time for their brain to adjust or do they earn more trust by “fixing” the problem now.
] Presumably the venting will be too large, based on your experience. I am allowed 90 days for venting adjustments @ no additional cost, anyway.
It seems that there was indeed a comb effect with the domes.
It was just an insight. 