OK. So I have age-related (noise-related?) ski slope high frequency hearing loss but reasonably good low frequency hearing. I wear ReSound Quattro’s and have been fitted with medium open domes. My audi assigned me the global user profile of “First-Time User,” which backs off my prescribed fitting in the All-Around general purpose (use it all the time?) program to avoid overwhelming a new user with new loud sounds. I’d rather be closer to my prescribed fit (~by NAL2) so I changed my global profile to “Experienced (nonlinear)” which at the very least puts more gain into the midtones.
My problem is that through the open domes a lot of low to mid frequency noise goes directly to my ear drums and my HA’s don’t have a chance to use their DSP power to deal with it.
Mark Chambers in one of those “thought” discussions predicted that power domes would not have a big effect at occluding outside noise but I said I’d be willling to take even a few dB of reduction to the bank.
So here’s what I’ve found so far on Day 1 with supposedly official ReSound medium power domes bought on Amazon to replace my medium open domes.
The bottom line, so far, is everything I hear is “more muffled” - because I’m not hearing two things at once. I’m hearing more through my HA’s and less directly to my eardrums. Sounds that I want to be relatively soft like opening and closing the microwave door are softer. But my impression is that everything I hear is noticeably cleaner and crisper. Voices with noise in the background seem much crisper (I could just be enjoying a great placebo effect!). I have noticed since that I’m hearing less directly through my ears that I’ve lost a little bit of spatial directionality, depending more on the mics behind my ears to provide that, but it’s a relatively small price to pay for my perception of crisper easier-to-understand speech.
But perhaps the most important thing I’ve found is that the mechanics of implementation are very, very important. Although in the ReSound fitting software the size designation of open domes and power domes is the same, the actual size of the lower, bigger mushroom on a power dome is several mm larger in diameter, making the fit in the ear canal much tighter.
A tight occluding fit in the ear canal means several things (at least to me). The inside of your ear will be more moist, softening the wax more. The larger size of the medium power dome as compared to my open dome means when I’m shoving into my ear canal, I seem to plow through more wax and I seem to have less control on making sure the receiver opening is centered in my ear and not blocked by wax. The first time I inserted the power domes, I had a really occluded bottom of the ocean sound (but I still noticed the cleaner crisper sound of voices).
With Sports Locks (concha locks) on my receivers, I’ve had the problem in putting on domes with the Sports Locks riding up towards the receiver openings and preventing me from realizing I don’t have the domes pushed fully onto the receiver ends.
So whaddya know?! When I decided maybe I should try to remove the power domes, see if they were occluded by wax and then reposition them in my ears, the right receiver and dome came out easily, since my ear canal runs forward in my head for that ear (the usual direction). But the ear canal for my left ear is unusual, it goes in and turns to the rear. Perhaps due to ~L-shape, the amount of sticky softened wet wax from the occluding dome, and maybe not getting the dome fully on the receiver, when I gently tugged to pull the receiver out, there was a lot of resistance and a big pop! Ouch! The receiver came out and the power dome was still glued in my ear (moral of story: if you wear medium open domes, buy small ReSound power domes, I think). I gave my physician wife a big pep talk: a trip to the emergency room or my audi might cost $$ money and if @Mark_Chambers wife can do a skillful job at it, you can learn, too! I found a set of forceps with a fine but rounded blunt tip with a raised serrated pattern on the gripping surfaces and laid my head flat against a table so as not to move. “Sterilized” the forceps tips with an alcohol wipe.
After a successful “operation,” the wife advised me on future insertion/removal attempts to tug the ear lobe backwards and a little bit up to open up and “straighten” the ear canal and remarked “you have very small ear canals!” (wife says everyone’s ears are a little bit different so the recipe for anyone else’s ear might not be the same)
So now that I’ve “cleaned” my ears by softening the wax in my ears with occluding domes and pulling a lot out of wax on the domes on first removal, things sound a lot less bottom of the oceany and perhaps with the pulling backwards on the ear lobe suggestion I’ve managed to reinsert the occluding domes with the receivers better positioned in my ear. I’m going to order small power domes.
The point of this is in open domes vs. small domes, a lot may depend on just getting the right size domes and inserting them properly into your ear and not plowing up a ton of wax into and onto the domes in the process. I have never ever removed so much wax from my ears in withdrawing open domes.
Now I am enjoying cleaner, crisper sound as noise direct to my ear drums does seem to be reduced. Since I’m not hearing as much of two sets of sounds, soft noises don’t seem to be as loud. If I amp up noise reduction, I can better suppress for instance the noise of a refrigerator humming in the background.
I think Mark Chambers is absolutely right. This is not a miracle completely preventing noise from bypassing my HA’s but it’s at least a few dB step in the right direction. I like it so much so far that I may wear the power domes all the time. With the oversized power domes, there is more of a sense of something in my ears, more annoying pressure when I chew, yawn, or whatever.
I haven’t found the volume too loud on my normal volume settings, perhaps because I’m missing some of the sound volume that used to go through my open domes directly to my eardrum. I’d advise anyone who emulates me to best consult your audi, probably start with domes that might be too small rather than ones that might be too large, and probably not a good idea to just let anyone with any old instrument mess with your ears if you lose a dome like I did. You’re taking a risk with your hearing but I accidentally had a good tool and a wife who regularly inspects people’s ears as part of her job.