Oticon fitting rationale

I was fitted with oticon opn1 iic about 8 months ago. During a routine check-up a few weeks ago I noticed (in the fitters genie2) that I was fitted with NAL-NL1. I requested to try vac+ because of the availability ofsome additional settings for soft voices. after about a week with vac+ I went back to restore to NAL-NL1 because with both vac+ and NL2 I felt like my head was in a barrel.
I wonder if anyone knows what I’m potentially missing staying with the much older NL1 rationale.

Just to clarify, I am very happy with the existing NL1 fitting, but have slight difficulty in understanding soft female voices in noise.

I cannot tell you how to do it but I know that my Audi did some extra adjustments, that has given me my hearing back to the point I feel like I am hearing very close to normal again. He has set my aids up so I have and only need the default program. I can hear in noise extremely good, and I also can hear soft voices good. What I think he said he did was to make the transition times faster than they were, and to give me the highest speech to noise ratio that was possible. I have ITE hearing aids with 2mm vents, if that helps you to understand my settings. I do not know which hearing plan he used, I just know I can go from a very quiet place into a very noise environment with ease. I have no issues with road noise or wind noise either.

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This is what your gains look like with NAL-NL1 (open fitting):

With NAL-NL2 Non Tonal:

NAL-NL2 Tonal, sometimes used with those speaking Asian languages:

With DSL v5:

The NAL-NL1 seems to be giving you more gain at the lower frequencies like 1 kHz, and less in the higher ranges, compared to NL2. All of the NAL options are using quite a bit of compression. The top curve in the graph is the gain applied to soft sounds, normal the middle heavy line, and the bottom lighter one the loud sounds. In other words soft sounds are being boosted, and loud ones attenuated compared to the normal sounds.

You may also want to give DSL v5 a try. It would be boosting the high frequencies more (perhaps helping with female voices) and also uses much less compression. How it will sound, can only really be determined by listening to it. My thoughts are to get the best formula first and then start asking for manual tweaks.

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Thank you very much!

Are you using an open fitting? Sometimes the head in a barrel sound can be the result of occlusion from a fitting that is too closed.

What I was trying to get across is that there is more to a fitting than just the prescription settings, there are lots of other magical settings that are there if your Audi know them and understands them or is willing like in my case to call Oticon to get help.
I keep notes on my hearing and hearing aids, I note what is working and what isn’t working and I email those notes to my Audi every now and then, he will email me back in a few days and say that he has a recommendation for an adjustment to my aids that can help. He is very honest and tells me that I am also helping him understand the fitting software better because I make him dig into it more.
I go to the Veterans Administration Clinic here about 30 minutes from my home, and I also voluntary at the clinic helping other veterans that need help and are just getting started with hearing aids. Being patient is one of the most important things I can recommend. And being honest with yourself and your Audi, and not being afraid to ask for what you need when it comes to your hearing.

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iic with 2mm vent. no occlusion. I can actually manage a conversation with the aids in and turned off :laughing:

I see the Rexton software recommends a 2.5 mm vent with custom molds. The gains with NAL1 and the 2.5 vents. If you have the SAV system, you might want to try a slightly larger vent.

If your vent is actually 2mm, you can still have a setting that is for a different size. I found that the barrel sound when mostly away if I increased the setting to 2.4mm. So the program thinks it is a bigger vent. That may help the other base model settings - Vac+ and NL2.

Have your tried the speech rescue option yet. and it can be increased in strength as well.

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it’s an iic, I can’t control the vent

thank you for all the assistance and information.
due to the fact that the iic only has a single mic and no binaural communication, it is possible that what I am experiencing is the best case scenario. I am making an attempt to fine-tune what is already an exceptional experience with my HAs.

Ok, what I see in Genie2 is that for the OPN 1 iic, the default setting in Acoustics is 1.0 x 0.5 mm (oval) vent. There are other options of 1.7 x 0.8 mm and 2.2 x 1.1 mm. Each are oval vents. You may have been set as the default which is smaller than you actually have. Worth checking to see that the program is close. I have BTE but I had a default setting by the audi and it was way to small. I had the option of going a setting larger than the actual which sounds better to me. It appears you only have 3 size options and it would be the largest one that best matches the 2mm vent you have.

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I only wish I had your hearing. Without my aids everything that is speech is very much in the mud.

hmm, interesting. I have an appointment at the audi tomorrow. will check! :pray:

I’ve had some experience trying out VAC+, NAL-NL1, NAL-NL2, and DSL v5.0 Adult on my miniRITE OPN 1. That’s because I have the ability to have up to 4 programs in my miniRITE, so I just put the different fitting rationales in each of the different programs so I can toggle back and forth between them for A/B/C/D comparison on the fly. It looks like for the IIC type OPN, it can only have 1 program, so you can’t really do A/B/C/D comparison on the fly like I can.

To me personally, and I suspect it’s different to each person based on their different hearing loss, the VAC+ sounds the most natural to me. But I do resort to NAL-NL1 in a challenging noisy environment where I struggle to understand speech. The NAL-NL1 gives me a sharper edge on the higher frequency sounds, and this helps me with better speech understanding. The DSL-v5.0 Adult also gives me a sharper edge to help with better speech understanding, but not as well as the NL1. The NL2 and the VAC+ don’t seem to have this sharp edge, hence they may sound “duller” for you, hence the impression you have with being in a barrel with these rationales.

I think the perception of how one likes a particular fitting rationale, beside how well it works for one’s particular type of hearing loss, there’s also a factor of familiarity involved. Since I was originally exposed to VAC+ first for a long time before I discovered that I could add in other fitting rationales in other programs that allows me to change fitting rationales on the fly, I might have tended to find VAC+ the most naturally sounding rationale to me, just because I’ve been more used to it, so that’s the “normal” way for me to hear, translating to being more “natural” sounding for me to hear.

In your case, on the other hand, since you’ve been more used to NL1 from the get go, it’s probably has become the norm for you, hence your preferred go to rationale. But I think it also does offer a sharper edge, at least based on my hearing loss, so that’s why the VAC+ and the NL2 sounds duller, more like in a barrel, for you. I think if you want more help with softer voices, the sharper NL1 is probably best at giving you this edge already, so I’d just stick with it if I were you. The soft sound perception control that VAC+ allows you to adjust basically does a similar thing anyway, because that adjustment allows you to select between varying degrees of “Comfort” (meaning softer tones) on one end, and “Detail” (meaning sharper tones) on the other end. So the NL1 is probably already giving you the most “Detail” setting by default in this rationale. So even if you were to switch to VAC+ to be able to boost up the Soft Sound Perception to the most “Detail”, it’s really already the same, or maybe not even as sharp, as the NL1 anyway.

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One thing I have noticed when using the different fitting formulas is that it is really hard to generalize what they do. What each of them does changes based on the type of the loss; reverse slope, cookie bite, or ski slope. I suspect that is why there are no really good comparison articles on them. I have read a few, but always come away with no real conclusion.

@Volusiano, Thank you for those insights!

I went to see the audi yesterday and here’s a “strange” twist. I looked at the simulations Sierra shared and the feedback estimate. While at the audi I noticed that the feedback graph in genie2 was very different from the simulations. it restricted gain much more aggressively. After giving this some thought I decided to try to improve the acoustics of the HA.
I put a thin strip of bandaid on the HA to increase the size and reduce any leakage and input of external sounds. The effect is dramatic! I can hear so much clearer. I wonder if the iic can be changed permanently. I am concerned about hygiene of the bandaid solution.

The simulations I was doing for you were for a RIC type hearing aid, not iic. Suspect because the vent is much closer to the microphone on a iic, feedback is much more of a problem… I will look and see if my Rexton software can simulate an iic device.

Tried with an iic, but it did not highlight any feedback issues. Kind of looks like that feature is not enabled in the software.

regardless, improving the isolation made a big difference