In situ versus REM


#1

Many of the new hearing aids offer a feature called in-situ audiology. It would seem to be a form of REM. What are the pluses and minuses of in-situ audiology?


Hearing test through hearing aids
#2

First of all, with in-situ audiometry, you can generate an updated and free audiogram at the comfort of your own home as often as you want, without having to go have a provider do it for you. Of course it won’t be a comprehensive one that would include bone conduction loss testing because you don’t have equipment to do that.

I wouldn’t call it a form of REM, because REM generates test sounds for the HA to pick up and its performance to be measured against target goals. In-situ audiometry doesn’t use the HA mic to pick up external sounds, which is half of the exercise to the HA that’s not done. It only generates internal test tones from the HA for your ear to determine where the threshold levels are.

Now if the amplification of the HA is off by a bit, then you’d have to crank it up louder than normal before the you can reach the threshold level. It may make your hearing look worse than it really is. But nevertheless it will cover the deficiency of the HA amplification by overcompensating for that through the newly prescribed values. I guess in a way, this is kind of equivalent to making the adjustment on the HA to hit the REM target.

If your in-situ audiogram looks almost exactly like your official audiogram, assuming that your hearing hasn’t changed much in between the two tests, then you can conclude at least that the HA is delivering the level of amplification on par with the calibrated test equipment used in your provider’s office for the audiogram.


#3

Is it true that running insitu uses your current amplifications? Or is it that it starts it all kinda fresh and you find your points?
I used it and having tinnitus I could take my time finding the exact loudness to detect the tone. The higher frequencies came in a bit more optimistic than the official audiogram.

But no I wouldn’t call it REM.

But nor am I a professional.


#4

For the Genie 2 in-situ on the OPN, it starts fresh and you find your points. But it shows the current audiogram points as reference points, and the new points are superimposed on top for comparision.

Then after you’re done, you’re given an option to re-prescribe based on the new result or not.


#5

Yup. That’s what I thought with Connexx with my KS7’s. Thanks.


#6

Also, in-situ is only a test for audibility. It does not ensure the power and compression provided by the device is adequate to meet mid-level and high gain targets.


#7

Presenting tones to yourself is also a big alteration in the standard definition of a pure tone threshold, against which all research has been done.


#8

Because you know you’re presenting the tone?


#9

Again, I’m no professional, but being tested was frustrating having tinnitus, obviously for the higher frequencies. Doing my own in-situ I could confidently recognize when I was hearing the tone or not by going up and down with the volume at my leisure to find the exact volume that I can hear the tone.
During a test, I mention this frustration but of course they want me in and out of there fast so they can get on with selling me a product and on to the next customer.


#12

what if insitu is different than audiogram with custom molds? especially with low frequency. since my audiologiest not using insitu and rem. just audiogram and fitting software if it can yield good result then i shoud go back to him atleast to use insitu


#13

Yup, for sure insitu is going to give you different low frequency results with vented molds or open domes because the lows are all just leaking out. Again, does not represent your hearing thresholds at that frequency, which are what targets have been developed for.


#15

I’m not sure what you’re asking, but it sounds like it is going to oppozite way from what I would expect, which I cannot explain.


#16

Residual volume different venting/leakage. Not everyone tests with inserts either.


#17

On the audiogram side, you mean? You’d think they’d catch it with bone conduction?


#18

Yes, you’d think so, but BC is increasingly being ignored. Especially with the drive towards OTC aids - the added complexity doesn’t fit with streamlining the fitting process.

That left audiogram has all the characteristics of a basilar membrane with potential dead-spots.


#19

Ugh. That goes against my general optimistic view of the world.


#20

Mine too, it’s a dilution of the process.

It promotes the average, when we ought to be aiming to get the exceptional from the best technology.


#23

From the discussion above :

Observation: Insitu with a closed domes gives better results for low frequencies than audiogram

Apparent Logic : Closed domes helped in preventing leakage of low frequency sound. (The real low frequency threshold is then closer to the insitu one)

Question for professionals : Doesn’t it make the conventional audio-gram less reliable for low frequencies? Are the low frequency threshold differences between audio-gram conducted with headphones and ear canal sealing ear plugs considered / corrected in general?

:


#24

I did my insitu using power tool kinda earmuffs over the aids and ears. Like the big old style headphones. I use open domes.
I saw some improvement in the higher frequencies because I could take my time deciding at what volume level I could hear the tone what with my tinnitus getting in the way.


#25

Those things aren’t related, the basilar membrane is in the cochlear. High frequency dead spots are easy to spot as they tend to occur at points of significant noise trauma (@4KHz for example). Low frequency dead spots are much harder to determine as the hair cell responses overlap each other to a much greater extent.

@Neville was suggesting that if you’d provided a BC result it would have identified the variability in the level being from a mixed (partially conductive) loss. Whilst my original assertion was that it was a test/leak error as there was no indication whether inserts (vs headset) were used. The other suggestion of the LF dead-spot is that testing variation can occur depending on the LF overlap and it yields a pretty similar reverse notched audiogram, which doesn’t respond to the ‘classic’ prescriptive gain models very well - simply because the Audiogram is a poor representation of the underlying loss: you’re almost better programming the aid to a flat 40-50dB loss with a REM/Live speech window open and just dialling up the sound manually while talking and providing a few noise stimuli.