To vent or not to vent a mold / mould

@GLl said:

For 5 years I have had a small vent in my ear mold. When the mold cracked (left ear) I had to go to a new audi since the audi who made the mold left the area. This audi had a mold made for me without the vent. When I asked about it, she said I would get less feedback. The mold must not have been tight enough since I still had feedback. When I started looking for a new aid I had a mold made for the other ear. This mold didn’t have a vent either and was very tight so no feedback. When trying the new aids, I had a lot of problems with base sounds especially in my left ear. I also began having headaches. I gave up the aids since I couldn’t get relief from the over powering base (there were other issues). Now that I am back with my old aid while looking for a replacement I found my right ear was giving me an earache and I had to keep taking the mold out to relieve the pressure. I’ve changed back to my old mold with a vent and the pressure and earache have gone away. Is it possible that a vent in the mold relieves some of these problems?

The “overpowering bass” you describe might be the occlusion effect, which is that ‘in a barrel’ sound that results from having your ears plugged up. It’s a huge reason many people don’t like hearing aids. Having a vent in your molds will make a huge difference, as you’re discovering with your new, unvented molds vs. your old mold. The size of the venting is another factor…I get quite occluded with smaller vents but do fine with something just a bit bigger. Too big and I lose ALL the bass, so it’s a delicate balance according to your hearing loss. Any knowledgable audi or HA dispenser will know this stuff, and I can attest to the fact that many do not, or will downplay it in order (it seems) to make a sale without having to have a mold re-made. You should find a more knowledgeable professional, or at least insist the molds be remade with proper venting.

Thank you ABB & Melissa for taking the time to reassure me that I was doing the right thing in ordering a new mold and having a recent one replaced. I thought I read something about the base, but I couldn’t find anything when I did a search. Guess I didn’t know what to call it. Strange my audi never said anything about the base problem when I was complaining about it with the Phonak Naida trial. I remember some of my old molds having larger holes with plugs of different sizes, but I trusted the audis knew the latest technology when my mold only had a small vent. Since the plugs didn’t always stay in place and I lost them, I was kind of grateful for the small vent in the mold. I couldn’t understand the no vent and I asked, but like I said, was told it would help the feedback problem. I think I’ll do a search on occlusion effect to understand it better.

Google “occlusion effect venting” without the quotes and you’ll get a lot of information. I learned what I know from the internet, and did the search myself when I couldn’t figure out why I could hear my own footfalls (like bass drums in my head!) when I was trialling a pair of aids with TINY vent holes. I remember googling it and finding a research article that demonstrated peoples’ objective reactions to molds with varying sized vents. It’s literally a science and the professional must be versed on what kind of loss you have and several different things. Some of the findings were subjective to the person wearing the aids (you and person A may have the exact same loss but person A can wear a slightly smaller vent, for instance) but for the most part you want as big a vent as possible for the loss to eliminate the occlusion effect. In fact, when my aids were ordered, the audi wrote AS LARGE AS POSSIBLE under VENT SIZE on the form. This was so the tech at the Phonak lab would match my loss to what he/she knows about venting when configuring my specific molds. Other audis whip out a little contraption and measure the vents on my old aids.

@GLl said:

For 5 years I have had a small vent in my ear mold. When the mold cracked (left ear) I had to go to a new audi since the audi who made the mold left the area. This audi had a mold made for me without the vent. When I asked about it, she said I would get less feedback. The mold must not have been tight enough since I still had feedback. When I started looking for a new aid I had a mold made for the other ear. This mold didn’t have a vent either and was very tight so no feedback. When trying the new aids, I had a lot of problems with base sounds especially in my left ear. I also began having headaches. I gave up the aids since I couldn’t get relief from the over powering base (there were other issues). Now that I am back with my old aid while looking for a replacement I found my right ear was giving me an earache and I had to keep taking the mold out to relieve the pressure. I’ve changed back to my old mold with a vent and the pressure and earache have gone away. Is it possible that a vent in the mold relieves some of these problems?

With an loss like yours, it’s not surprising that your provider would order tight earmolds without a vent. In your case, it seems, a vent is necessary. You should have the earmolds remade with small pressure vents - you might even want to request a looser fit.

The audiologist is also probably setting the low frequencies too high. You might want to tell him/her about this. Oddly enough, experienced users with severe to profound losses don’t seem to care much about high frequencies either. My guess is that your high frequencies could be reduced to suppress feedback without much impact on speech intelligibility. Good luck!

@Melissa said:

the audi wrote AS LARGE AS POSSIBLE under VENT SIZE on the form. This was so the tech at the Phonak lab would match my loss to what he/she knows about venting when configuring my specific molds. Other audis whip out a little contraption and measure the vents on my old aids.

Do each manufactures of hearing aids make their own molds? I thought molds were generic.

True, drilling a hole may be all that’s required. But again with your loss a vent may cause feedback problems. There’s only one way to find out, but it is something to keep in mind. Miracell can be purchased on line, but my first bottle I got from my audiologist. A little goes a long way so a small bottle should last for quite a while.

@GLl said:

Thanks for taking the time to answer. I may need to look into the product called miracell since I am sure the new mold is going to be tighter. Where does one get this? Lucky for me one of the molds was within the time limit to change it at no cost. I was told all that needed to be done was to drill a hole. The other mold I am paying for. I’ll now have two molds for my worst ear and can switch to the no vent if I need it. I’ve notice with the newer hearing aids the feedback is a low growl, not a high squeal. Much easier to tolerate than a headache or the pressure build up.

The low growl is probably because the aid was set with the frequencies around 500 Hz too high. You may be able to get rid of that by reducing the gain in that area, or by turning the low frequency boost off if it’s set to “on.”

You ear mold should have come with small pressure vents even with your hearing loss because your old ones had it. It’s easier to to close off a vent than to drill one at the audi’s office, or worse, sent it back to the factory.

@GLl said:

Thanks for taking the time to answer. I may need to look into the product called miracell since I am sure the new mold is going to be tighter. Where does one get this? Lucky for me one of the molds was within the time limit to change it at no cost. I was told all that needed to be done was to drill a hole. The other mold I am paying for. I’ll now have two molds for my worst ear and can switch to the no vent if I need it. I’ve notice with the newer hearing aids the feedback is a low growl, not a high squeal. Much easier to tolerate than a headache or the pressure build up.

Miracell is sold as an ear lubricant and an anti-itch agent. You can get it through the internet and some hearing aid dealers will sell it. If you’re looking for a lubricant, I would suggest using glycerin, which is sold in drugstores as a skin lotion.

If you’re looking for a more secure fit on your hearing aid or want to suppress feedback, I’d recommend a product called “Cushion Grip.” This is a denture adhesive which you might be able to find in a drug store or on the internet. The product works by building up the canal part of the earmold or hearing aid and creating a secure fit. Cushion Grip is a unique product and other denture adhesives will not work.

Cushion Grip will work well with hard earmolds but is not suitable for soft earmolds. First clean the aid of skin oils and squeeze a small ball onto your finger and shape in to a rope by rolling it between the thumb and index finger. Wrap the material around the middle part of the canal section of the earmold and flatten it a little to insure good contact with the aid. I like to then rub on some glycerin to keep it from sticking to the ear canal and make inserting in to the ear easier. You don’t have to do this but you will need to keep the earmold in the ear for a few hours while it sets - if you pull the aids out too early, some of it will stick to your ear canal.

Push the aid into the ear and apply pressure so that the material conforms to the shape of your ear canal. If you do this properly, you can achieve a good seal without having an earmold that is uncomfortably tight.

A application of Cushion Grip should last a few months. In some folks, it gets brittle and flakes off. Clean the material off and repeat the application any you’ll be good to go. Going this route means that you can reuse even very old earmolds and get a comfortable, secure fit - just make sure your tubing is replaced regularly.

It’s true that feedback is reduced when molds are not vented. It’s also true that the ear’s ability to compensate for pressure changes is also reduced. I can tell when my mold vents are plugged with wax by the way my voice sounds. I can also detect a thumping sound when I walk. Wax is always the problem. I just use compressed air to blow the wax out. I recomment mold vents even if feedback is an occasional problem. Newer digital aids can handle the feedback issue. Also newer aids have highly vented speakers deep in the ear. No ear molds to deal with. I’m getting a set of those soon. Jim Hinkson

@bherring1964 said:

I would recommend you asking for a “pressure vent”. They are tiny but equalize the air pressure and reduce occlusion.

That was done and today I picked up the new molds. What a difference! It is like my old aid is new again. Speech is clearer and I can turn my aid up without the feedback. Thanks everyone. In the future I will be sure the “pressure vent” is added since, like someone said, it is easier to plug the vent up then to send them back to add holes.

@ABB said:

Having a vent definitely decreases the amount of bass. My hearing is imbalanced and I have a small vent in my left ear which keeps more bass sound in and a larger vent in my right ear which doesn’t like the bass sound. Ideally, your audiologist should have a large vent put in your molds that can be capped with these little plastic plugs that come in varying sizes of vent holes, by experimenting with the various sizes, you can find the one that gives you the best sound for that particular ear - obviously I’m no professional because I don’t know what these things are called! As for the vent decreasing the pressure in your ear, that makes sense to me, but I’m sure one of the audiologists will chime in. You may still get a little feedback because that can also come from your hearing aid being at its max power.

You may be ‘no professional’ but you are quit right. You can get a variable vent and then alter the diameter of the vent with the little ‘corks’ with holes in.

But lesser quality hearing aids are more likely to produce feedback.

I am three exceptions to the “as large as you can go for the loss” venting rule.

One is that I have worn hearing aids a very long time, and back when I was little feedback management was very bad so I wore full moulds. I’ve had problems with sound quality whenever I’ve had to wear skeleton moulds.

Two is that I use FM a lot, and the main point behind that is to block out environmental noises and listen only to the input coming through the FM system. Too big a vent lets in too much external noise.

Three, the most important for me, is that because I have a mixed loss and one side has a greater conductive component than the other, I have internal occlusion as part of my loss. There is more of it on one side than the other, and if I don’t block up the other ear tightly enough it sounds like I am shouting into one side of my head.

I have trouble getting enough occlusion!