Real ear measurement vs. in-situ audiometry

Nevelle told me many years ago that most self programmed hearing aids are under fit, not enough gain or volume.

My thoughts on this are the Insitu fittings are under fit because of the manufacturers proprietary algorithms being a little low concerning gain.

So fitting with RIM will consistently need a little more gain to satisfy the RIM targets. This can be uncomfortable for many until acclimated.

Please correct me if I am misunderstanding this.

@Neville said:

And this is what the proprietary rationale is built for. Minimizing returns across the large number of clinics that do not follow preferred practice.

Consistent with “Fitting and Dispensing Hearing Aids, Third Edition”:

That agrees with my worst ever button pusher over Thanksgiving with Resound One 9 trial. The speech performance was no where near what I needed.

Not quite sure I understand. Is RIM Real Ear measurement or something else that I don’t understand?

Yes, manufacturers tell you to verify against NL2. You can also verify a proprietary rationale against DSL, but because they are all based on NL2 it just requires a lot more wrangling. Recall, rationales are just gain targets, so it can certainly be done. It will just start out further away and you have to make more changes to get to DSL.

No manufacturer has ever once suggested to me that a user might have a better experience with their proprietary rationale. It’s not an expectation.

@Volusiano said:

Sorry, but I honestly don’t get the point of this question. OK, so I think my clinician who sold me Oticon HAs is talking to Oticon when they “call the manufacturer”. It’s really over my head the implication of this question.

Just because I wanted to de-mystify it a bit. They are talking to an audiologist. An audiologist who has better knowledge of the particular product and is employed by Oticon to help out other clinicians. But they are still providing audiological recommendations, just with a deeper understanding of the product than some clinicians have.

I think I answered your other question above (or in another similar thread right now?) Manufacturers typically develop proprietary fitting rationales to try to minimize returns in a young industry that has a lot of weak providers. Keep in mind that they are also international, and as much as many users of this forum struggle for access to good hearing care, there are a lot of other countries where that access is much worse.

But you bring up a good point–there are individuals who are part of a ‘small population’ of hearing loss for whom independent targets have not been developed. If a manufacturer can say, “Hey, we did this for you and incorporated the results into our proprietary fitting” that is absolutely a sales feature. On the other hand, I don’t think you’re on the right track when you suggest that their proprietary rationales are also circumventing weaknesses in their devices. If their device cannot manage two of the most frequently used systems in the world then they have a real problem.

@Neville said:

I don’t think you’re on the right track when you suggest that their proprietary rationales are also circumventing weaknesses in their devices. If their device cannot manage two of the most frequently used systems in the world then they have a real problem.

Thanks for your answers, @Neville . I agree that mfgs wouldn’t use their own rationales to circumvent weaknesses in their devices, because there shouldn’t be any weaknesses and the minimal standard should be to be able to perform to par with the standard rationales at the minimum in the first place.

It’s more often likely the opposite, where they have strengths in their devices that cannot be optimized with features or parameters that can be shared with the standard rationales, so they use their proprietary rationales to incorporate those special strengths from either their hardware devices, or from the proprietary knowledges they gain through their research into the implementation of their own rationales (like with how they might have chosen to handle the cookie bite loss differently and incorporate it into their rationales as they’ve indicated in that educational video I mentioned earlier).

Only book I saw mentioned was on post #86 Fitting and Dispensing Hearing Aidsemphasized text**
I’m not familiar with it, but in general increasing your understanding of what you’re doing is good, but I wouldn’t expect it to give specific remedies for different sound qualities. All of the HA programming software I’ve seen does usually have a section that deals with recommended solutions.

Thankyou Mdb, the problem I have is I always seem to be moving away from the starting point ie using audibilty fine tuning makes it worse.
I think it may be a REM issue, trying to reproduce a regime fitted with it but only using in situ.

There should be a section in the software that is aimed at basic issues and offers suggested solutions. Is that what you’re talking about? In Phonak’s Target software it’s called Automatic Fine Tuning. DIY section of the forum is likely a better place to get more info.

I think this is an area of programming that is more art than science. I’d suggest describing your issues on DIY section of forum and seeing what suggestions you get. I’d expect a fair amount of trial and error. There’s also the possibility that there’s something wrong with the hearing aid. Unless sound quality issues are extreme, one can often get used to them and they become the new normal.

Yes I think I will have to bite the bullet one day. I’m trying to reproduce the sound of a much older aid which has been a friend for five years.
I thought about asking for a library of sounds which represented " hollow and tinny" or “dull” or "incomprehensible "but then what would I be listening to them through?
If I were talking to an audi I’d have trouble describing what i was hearing, apart from lisping.
Don’t think it’s the aids, same results on three pairs all phonak like my NHS originals.

@MDB said:

I think this is an area of programming that is more art than science.

It is a subjective matter as well, with limitless possibilities of bias, uncertainty, and miscommunication. That is the main reason I rather take the empirical/DIY path in most cases.

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