Costco KS8 first impressions



szcas3, what is the difference in domes from Resound to KS8 and how many KS8 domes have you tried?

Your story is the same as mine, including the vacation bit, except I had Rexton Cobalts and am into KS7.

The Rextons have 10mm closed domes and KS7 has Click Sleeves which I cannot wear more than 4 hours.


Glad to hear someone else has this problem,but not happy that we are going through this. I really don’t know what the differents is,but I will ask that question tomorrow. The Resound domes are very easy to just slip into my ears,the KS7 and 8 were either to big or this one I have now is small but still has lots of fee back and can’t hear the TV as well as before and my left ear is sore,I did not wear them at all today,they are the open domes,but the closed does seems to help me hear better,but there is the feedback problems also. I am guessing when I get back from my vacation I will have to do a step up to the Resounds or something that is close to it. I just hope I can get on the ship and try my best to hear what people are saying to me,I will use my old resounds I think on the trip,


I really think my problem is a size issue. The first time they went in, at the fitting, it was a struggle but my ears were sensitive from all her poking.

I have a high pain threshold and am not a quitter so forged on. The first week, I just concentrated on adjusting to the new volume and sounds. I over came the headache issue, previously posted about.

When I first got my Rextons 8 years ago, I wore them long hours from the start. They were my first aids and in a month I didn’t know I had them.

This time, I am constantly aware of them, which I don’t like, at all. It’s been like going from a thimble to a sand bucket.

The past 7 days the only way I could comfortably put them in was by putting baby oil in the canal. At 4 hours my ears were sore enough to repeat the lube job and stretch it to 8 hours.

Yesterday (Wed.) I became concerned that my ears might be inflamed and my next check up, on Monday, might be less than ideal. So, yesterday and today, I just removed them at 4 hours and will now go with my old ones until Monday.

I do believe, if we can get domes right I will be ok.


I use 10’s in the left and 8’s in the right due to some discomfort from the domes that doesn’t happen in the left.


Don’t all of these aids use the same receivers, and therefore the same range of domes, click sleeves, etc.? I’m pretty sure this is so. So you could get Costco to give you what you need.

In fact, I just went into my local Costco today and got a pile of click domes – not the sleeves.

When I first got the KS7s, it took three tries to get the size of the domes right, because my ear canals are sort of strange, and because I needed the (physically larger) power receivers because of my low-frequency loss. In the final end, the 10 mm closed domes have worked fine. I can wear the aids all day and forget they are there.


Before I go on, I hope the OP, Pleaides, isn’t too upset with where we have taken his great thread.
I wondered about that as well so just took a look. The burgundy Rexton has an 2M receiver and the KS7 has an 2S. The 2S is slightly shorter.

I think she changed the KS7 from stock to accommodate the Sleeve which I think is a little different (thicker?) in the nose end.

Tomorrow I am going to try the 10mm closed dome on the KS7, just from a comfort perspective because I think the KS7 is programed to the sleeve. No?


If the type of dome / sleeve is changed, then the fitting needs to be reconfigured, too. Not redone – it’s just that the software will shift things around to match up with the changed dome / sleeve.

Here are the different possibilities for domes / sleeves for the KS7s, as shown in the fitting software. They all come in different sizes, too, of course.


Do you mean she changed used an “S” receiver instead of an “M” for this reason? This is kind of above my pay grade, but I think the receiver power level (S, M, P, etc.) is chosen to match your audiogram. But maybe that’s why she would have done it.

Only the single closed domes worked for me, because there isn’t enough clearance between the receiver and my ear canal with the double ones. So the receiver size does have an impact (although the P ones are a lot thicker).


I am a dumbo, so just thought she changed the receiver because of the dome. From what you say, I guess I’m wrong. On the other hand she said there was little difference in audiogram from previous but maybe it was just enough to make a change. I’ll ask.

Would she go from M to S for a slight loss?


@whahuh: If you imagine fitting your audiogram shape inside the dark grey area of the charts shown here then you can get an idea of what range of loss is covered by the power of the receiver.


Here’s a blown-up version of the curves. I note that it doesn’t have the click sleeves on it, though. I’d imagine that the vented and closed click sleeves would be similar to the open and closed domes, respectively. Maybe?


Well these are two different generations of aids. The Rexton uses the older version of the receivers, while the KS7 uses the current version. (You can tell this because of the different ways the receivers attach to the body of the aids.) So we are talking about different receiver generations, with, perhaps, different specs. So this might be an apples-oranges-type thing here.

As @z10user2 has suggested, there isn’t a “stock” version – the aids have to be fitted with the receiver that fits the user’s audiogram. And physical size, which is what the “2” indicates.


Thank you for the graphs, I was able to enlarge the pdf.
3 tests; 2010-2015 & 2018 virtually unchanged.
Both ears sit within darkest of the first graph, indicating receiver S, which is what I have.
But…that also indicate open dome, no?


Yes but it looks like one ear is right on the edge, 70dB down at 2KHz. I believe they don’t like to do that, that there should be some margin in maximum gain to allow for variations in the fitting. In theory, I should be able to use the M receivers. But the P receivers worked better, and made the Costco audiologist’s initial fitting easier.

So maybe that’s why you’ve got an M receiver for one ear, and an S for the other? I thought they tended to match them, if possible? But I’m stretching here, I really am.

Oh and you’ll note that the open/closed question only matters for low frequencies. In theory, the open domes should work for me. But in real life, they did not. Again, the Costco audi tried all this, but the closed domes just work better.


No, you misunderstood. The 8 year old Rextons had M and the KS7s have S.


@z10user2 thank you.


Thanks so much for this update. I’m just now starting to look for my second pair and trying to get as much info as I can about the different HA’s available at Costco. I appreciate the info!


I have the KS8T, and my batteries are lasting much longer. I’m on my 8th day - the ones that came with the originals. I have heard that leaving the tab off the batteries for about 1 min before putting them in your HAs helps.


I’ve had my KS8’s since April, and have found them to be the best hearing aids that I have had in the last 15 years of wearing aids. I found the Costco fitters to be as good or better than any provider I have used before, with a PhD audiologist in charge of the whole operation at my local Costco. Their equipment is first rate and their procedures are carried out carefully and thoroughly.

As for the KS8 aids, they communicate signals between the two aids, with the actual audio information transmitted through your head, and because of that, can determine the difference of arrival time to the four microphones(2 on each ear) from a source, and this allows for an excellent ability to “focus” the hearing aids forward or sideways or backwards where you want to hear from. Other aids I have had have claimed this capability, but these are the first that I have had that actually work.

I like to listen to classical music, and the streaming sound from my phone has allowed me to hear music like I did 15 years ago, beautiful and clear and precise. It is wonderful.

I think the KS8’s are doing very well at Costco, as a friend who lives in Manhattan tried to get an appointment a week ago and was told he could come in October!


Reviewing all these threads on the KS8’s is very interesting & informative. I’ve ordered mine and will be getting them 5 days from now. Looking forward to getting them up to speed and adjusted for my needs. Expectations are very high.


I’m testing the free Tunity app for streaming from TV to my KS8’s. Limited channels but very cool. Point app at TV and it finds the channel.