How to solve a whistling sound when wearing over the ear headphones with my miniRTE hearing aids

@Volusiano said:

I would at this point try something else. I would create a new customized “headphones” program that’s a copy of the default General P1 program, and in there you can start making adjustment to eliminate the feedback. If you already have the Feedback Management setting to Normal and it’s causing feedback, chances are you will also hear it if it’s switched to Low, but it doesn’t hurt to try. If Low doesn’t help either, you can try to put it back to Normal, then run the Feedback Analyzer WITH YOUR HEADPHONES on. This will ensure that the condition of wearing your headphones will be taken into account automatically by the Feedback Analyzer when it determines the gain reduction after the white noise scan, in order to guarantee no feedback with the headphones worn on your head.

Your gain margin will probably be reduced significantly (you’ll see a greyed out area on top of your gain curve in the Fine Tuning section (see example screenshot below), but it’s probably OK as long as you only enable this Feedback Shield functionality in your customized Heaphones program and not in the other programs. You can also experiment with either leaving the newer (Sound Optimizer) Feedback Management setting to Normal, or change it to Low or OFF to see if it makes any difference, but whatever you set for this, apply it only to your customized Headphones program, and leave it to Normal (or whatever it currently is set to) in the other programs if that’s how you have it right now.

@Volusiano I finally got around to trying this. I tried first the Feedback Management settings to a P4 program which was a copy of my general program in P1 i use day to day. I set it to LOW like you suggested but I still get the whistling like I reported in my original post.

I then reverted that and tried your second suggestion which was to run the Feedback Analyzer with headphones on to the same copy of my P1 that’s now in P4.

I did notice a mention at the bottom where it says “Settings will be applied to all programs”. Is there no way to restrict this only to P4 or am I misunderstanding what its saying on this screen?

Also as a comparison, here is the original charts before feedback analyzer I just ran and after (before is top, and after is bottom). I haven’t saved this yet to my hearing aids due to the concern of this applying to all programs, so i’m being cautious here.

Yeah, the new Feedback Manager (the Sound Optimizer one) can be set differently on separate programs, but the old Feedback Shield, if turned on, will be applied to all programs.

Have you tried to turn off the (new) Feedback Management in P4 altogether instead of just setting it to Low? The idea here is to isolate whether the whistling is due to the new Feedback Management’s fluttering trying to stave off feedback, or simply due to the analog feedback loop. If setting it to OFF altogether instead of leaving it on Low stops the feedback, then at least you know that’s the culprit. If setting it to OFF altogether still gives you feedback, then at least you know that you’ve eliminated that variable for good. But if setting it to OFF altogether resolve the problem for you (Feedback Management is the culprit), then at least you can turn it off in P4 and leave it on in the other 3 programs.

If you still get the whistling with Feedback Management turned OFF altogether, then you have 2 options:

1. If you still have access to your HCP and your Mores are still under warranty, I would earnestly try to get the HCP involved in trying to figure out why you get the buzzing in the Tcoil program, which you shouldn’t. At least to see if it’s a defect in your More, or just an interference issue around your house. If the earlier, then get new More replacements and use the Tcoil program for P4. If the later, then at least you know and maybe can figure out what the source of interference is later on when you have time.

2. You mentioned that some headphones cause the whistle but the Bose don’t. If you really don’t want to turn on Feedback Shield for all programs, then maybe just use the Bose.

3. If 1 and 2 are not attractive options for you, and turning on Feedback Shield solves the whistling problem for you with the headphones, and you find that you can live with it enabled and applied to all programs, then this can be your solution.

What you see with the shaded red and blue after you run the Feedback Analyzer is the margin loss that you will have to give up in order to activate Shield to prevent feedback. It means that the HA will not be allowed to amplify the gain into the shaded regions, because if they do, feedback most likely will occur. Usually, if the shaded region is not infringing into your gain curve, then it shouldn’t be too much of an issue in terms of not being able to amplify enough because it’ll cause feedback. But if it’s pushing down

It looks like the Feedback Analyzer determines that your region for feedback is the strongest at around 1 KHz, so it will suppress and not allow any gain to go higher than what the gain curves show, even if needed. You’re only choosing to show 1 gain curve here, so it’s probably the medium gain curve you’re looking at.

If you look at the screenshot below for my gain curves, you’ll see that I’m showing all 3 gain curves (the 45 dB, 65 dBb and 80 dB curves, for soft, medium and loud input SPL level in the Fine Tuning section). The tallest gain curve is the 45 dB one, because softer input sounds requires stronger amplification to compensate for my hearing loss in that frequency.

You can click on the dB button seen in my screenshot and select which or all gain curves to display. As you can see, my margin loss hugs right along my 45 dB SPL input gain curves, so if there are soft sounds coming in and I can’t hear them well and I try to turn up the volume to hear them better, I’ll be limited by this “blocking”/margin loss, and I may lose some of the audibility/clarity because my soft gain is now limited to a lower signal to noise ratio because Feedback Shield is suppressing and not allowing my HAs to amplify more into the shaded area if needed when I turn up the volume.

Another indicator is the Reserve Margin shown in the second screenshot below. You can see that I have lost a bit of my Reserve Margin, more so on the right aid than on the left because my hearing loss is worse on my right ear, to accommodate this Feedback Shield self-imposed gain margin limitation. For example, if I keep clicking the up volume from the default level, I may be able to only go up 3 clicks on my right aid before it gives me the “topped out” chime, while I can do maybe another click or two of volume up on my left aid before the topped out chime can be heard on the left aid.

I don’t know if the OP explored this route… but it seems custom molds could help given the blue and red feedback area in the pics above. I did not read all the comments, sorry if this is something that has already been addressed.

Great point! But only if the custom mold doesn’t have a vent, or else it’s for naught. But without the vents, occlusion may make it not worth the while, especially considering the OP’s hearing loss, in which vents are necessary to allow the low frequencies in.

But this leads to another great idea. Maybe it can be simple as taking a couple of soft plugs and simply plug up the ears over the receivers while wearing headphones. This will minimize the leakage out which is what is causing the feedback. With this solution, it only has to be applied when wearing headphones, so that nothing else will be affected.

Turning Feedback Manager to off seems to have solved it! I’m cautiously optimistic… thanks so much for your help @Volusiano. I am traveling tomorrow and hence using my headphones a lot during travel so will report back

In meantime, I’m curious as to whether this new P4 headphones program (which was a copy of my P1 general program) should have exactly the same settings except for disabling feedback analyzer. For example, when my Audiologist first setup my HAs she gave me a P3 program for music, which i never used just due to convenience. I noticed that program has these differences:

• “Neural Noise Suppression” disabled
• “Directionality” is “Fixed Omni” (vs. “Neural Automatic”) which makes sense since the neural noise suppression is off
• “Transient Noise Management” off (vs. Medium)

I assume that you will only turn off the Feedback Manager completely in P4 (which is now dedicated to headphones use), and will leave the Feedback Manager enabled (to Normal) in the other 3 programs.

The MyMusic program has those settings like that to minimize the effect of the signal processing, and the Fixed Omni gives you a wide open field without any effect on beam forming so that you can experience as open a sound scene as possible.

You can probably just turn off the Feedback Manager in the P3 music program and use it for your headphones as well. This way you can save P4 for something else.

Update: I tried the MyMusic program, which is actually a built in Oticon program, but tweaked it to disable Neural noise suppression, change directionality to Fixed Omni and disabled Transient Noise management too.

Music sounded so much brighter in this mode, more treble and midrange but lacking bass it seemed for some reason.

However, downside was I was getting feedback again.

There’s clearly a fine tuning difference I can see in the charts between my existing P1 and this MyMusic program. I’m not skilled enough at programming to know how to tweak the MyMusic to eliminate the feedback despite the other setting changes.

So I ended up ditching MyMusic, copying my P1 General into P3 and did the same ddisbaling of feedback management, neural noise and transient. Seems to work fine.

I wish I would figure out how to tweak the frequencies of this so I could get more depth to the music I’m listening to though

@bobbydigital16 said:

Any advice on how to go about this given how many frequencies there are? (And how I do this in the interface—is it a matter of just interacting in the fitting area table below the graphs?

If you don’t want to mess around with the Gain Controls parameters because they are too complicated, you can try to make the adjustments in the Sound Controls menu instead, by changing the Brightness Perception toward the Fuller on the slider scale. At least this way, it’s easier to undo things if they go sideway. You can also change the Soft Sound Perception in there as well. The only caviat is that your program(s) must be using the VAC+ Oticon rationales in order for these parameters to be available. If you choose one of the standard rationales, the Sound Controls menu will be greyed out.

@Volusiano said:

If you don’t want to mess around with the Gain Controls parameters because they are too complicated, you can try to make the adjustments in the Sound Controls menu instead, by changing the Brightness Perception toward the Fuller on the slider scale

Good advice Mr. V.
@bobbydigital16 have you explored the "Fitting Assistant?:

An excellent point from @flashb1024 to use the Fitting Assistant if you don’t want to mess with the Fine Tuning section directly yourself. I totally forgot about it.