REM: I may be a convert

I have consistently poo-pooed the use of Real Ear Measurements and Speech Mapping.

To me REM is simply a tool which adds work only to ‘prove’ that the hearing aid output matches a theoretical ‘target’ graph.

However I have just been to a presentation where a top researcher showed some test results: his team have found that some fitting software tells lies! The graphs on screen don’t always match the aid’s output!

I am not talking about minor differences - I am talking about worrying problems.

They have also found big differences in some batches of new hearing aids - especially with regard to directional mikes.

The researchers wouldn’t tell the names of the manufacturers concerned.

When fitting aids the researchers have essentially abandoned the manufacturers’ screens - they use the REM screen for ALL real work.

It also looks like ALL incoming directional aids need to be checked in a test box.

Now this requires some thinking about:

  • Dispensers (in the UK anyway) are bound by legal rules of ethics. So what do we do if we see that most open fits don’t delivery the advertised amount of say high frequency? Do we tell the client? Do we report the manufacturer? Or do we adopt ‘best practice’ and just do the best we can?

  • Do we need to ‘test box’ all incoming new aids? What do we do if we find a problem? Tune to match the aid’s real performance? Ask for replacement aids?

  • Do we need to ‘test box’ the client’s aids on every visit? Only if they have a problem?

  • The dispenser will need to REALLY understand REM, hearing aid technology, fitting algorithms etc … and in reality how many do?

  • Even if we use REM, does it REALLY give good fittings? Many dispensers find that REM adjusted aids produce a WORSE fit that the manufacturers’ first-fit software! (The National Health Service in the UK uses REM on almost every fitting. Do we see the NHS clients being happy with their digital aids? Err - I think not!)

  • Will dispensers need to abandon the manufacturer’s algorithms and set NAL-1 just so the REM box can check the results?

I can see that:

  1. I will have to buy a fancy REM box … top-end, as it will become my main fitting tool!

  2. I will have to allow more time for REM tests.

  3. I will need to set up an easy to use test box system : I will be testing aids every day!

  4. I will need to focus on NAL-1 in order to use a standard fitting target known to all REM boxes.

  5. I will have to devise a way of working which allows me to get the most out of hearing aids using a REM system … even if the aids have deficiencies and/or the client dislikes the REM testing.

  6. I will have to review all my financial and time budgets to allow for the extra testing time and hardware.

  7. I will have to review any legal / ethical issues involved.

Tricky stuff! I can see that over the next year the technique used in my practice will change greatly!

… but what about all those time constrained dispensers in the High Street stores … and the many dispensers who only make home visits … how can they take something like this on board ???

I have tried over the years many machines, the Fry Fp40 and the FP 35. The aurical both
VSP (not bad) and the Aurical and also looked at the Medrex and the Affinity this fine piece of equipment are built by fine eng. but they know little about practical fitting.

A while ago, I had a friend who said Audioscan was the best machine out there. I decided to give it a try. This One product company seem to know what they are doing
their equipment - while expensive it is really to use and very very easy to use.
While I recomend the Verifit - which is an amazing product- there is something call
RML500 which is portable.

Verifit is the only machina capable of verify frequency compression aid. It takes about 5 minutes to learn. If you can afford the verifit, the viewport allows to verify in 5 minutes
audibility, the use of directional microfones, Noise reduccion and feedback.

I admit, I use speech mapping- 95%. I would call 5 or 6 customers who are unhappy
and ask them to refit them using the verifit. You will know why we love it so much

I have an old RM500.

However it has no NAL-1 !

Also, I want cordless REM ‘earpieces’ for the client.

then you will be looking for GN - AVS. It is nice. but no where near
as good as Audioscan

Firstly:

Hallelujah!

Forget NAL, you are still putting the Cart before the Horse. You can still have the NAL target on screen if you wish, but measurement agains NAL involves a test tone/PRN - irrelevant for speech output through a modern aid.

Speak to Remco Vd Kruit at Progress hearing and get sorted.

Xbulder: didn’t the Verifit licence their speech mapping from Mex-Rx? As for them not knowing anything about fitting aids - granted the company didn’t originate from this area, but there are some good guys there who have turned fitting with their kit into quite an art.

audioscan never licenced Visible speech. It is such a small company that they decided not to file lawsuit against the big ones. VSM is based on the muller and cox work (i think)

The may point I think is that working with REM involves a TOTALLY new process … one which is NOT covered by standard training, which does NOT lead to a test & sale within 40 minutes, which is NOT really suitable for home visits, which is NOT suitable for poorly trained fitters and which requires rather expensive hardware.

it actually leads to sales, you will be able to help difficult cases

In-Situ testing like “Sensogram” or “AudioDirect” uses calibrated tones generated in the hearing aid to measure the threshold frequency response of the patient when wearing the instrument but it does not include the frequency response of the microphones. As a result estimates about the microphones, ear shape, etc. must be used to create an audiogram from the measured data.

However if the manufacturers provided an additional hearing instrument feature in which the instrument itself can be employed to participate in measuring the unprocessed microphone response of the hearing instrument (still in-situ), then the program (using the results of AudiogramDirect and this added “MicTest”) would have gathered complete information - enough to accurately plot hearing threshold against sound pressure. Since this added “microphone response” part of the testing would not require any response from the patient and since it is not a threshold test, it could be done very quickly and automatically at any sound level. This may mean the need for elaborate sound-proof rooms etc. may be minimized (only room resonances need be avoided).

The fitting program (i.e. iPFG) would automatically combine the results of the two tests and create an audiogram that did not rely on any estimates or assumptions. From there you could proceed into word recognition tests, recruitment tests etc. from a fully calibrated foundation.

Starkey have aids with an integrated REM feature. Fairly close in concept.

If I understand the Starkey approach it still requires that you slip a tube into the canal past the receiver. That tube goes to the instrument’s microphone that now doubles as a REM probe microphone. RECD is derived from it.

Using the AudiogramDirect/MicTest described no probe tube is used and the acoustic canal seal (or partial seal) is not affected. In other words your measurement process is not distorting or otherwise affecting the acoustic configuration that you are trying to measure.

I am not a pro in this field. But I would remind you that the Achilles Heel, the fallibility in fitting lies mainly in the threshold test results. While this test is probably fairly accurate for mild to moderate losses, it is apt to be grossly misleading for those with steep slope loss or severe/profound losses.

This is because pumping large amounts of test tones into those types of loss will inevitably result in false responses due to recruitment.

As they say in the data processing field…garbage in …garbage out. REM, MApping etc must have an accurate base of comparison to be meaningful. Ed

this is another example of starkey marketing. This is not rem or speech mapping , as you are not checking anything, you are just doing RECD. Yes in principle it will make the instrument sound better as it will take into account individual ear canal difference
but it will not be REM. PHONAK had this a long long time ago and it was properly
call RECD direct.

I haven’t checked, but I recall someone saying that Starkey RECD had been upgraded recently to proper REM.

Or was I imagining that?

You are correct.

Their current implementation is measuring the real-ear aided response, per this Hearing Journal article:

You’re quite right, but then you’d end-up fitting Starkeys…

You don’t need to modify your entire sales process, you still test as now, run your fitting as now, while you have an open REM live speech window. Observe the modifications to the output, cross check with the patient and save your settings to the aid.

Patient sees the performance on the screen, you see that you are doing a good job; then voila you go home knowing the patient is fitted as well as they can be.

the point of rem is to have an Independent way to verify your targets.

I was just fitted today at the Seattle VA with Phonak Exelia Art Micros and she made extensive use of the REM machine (and the Icube). We’ll see how well it works…

years ago, on the HOHadvocates forum, and you jumped all over my case, several times. Told me I didn’t know what I was doing, probe tube tests were not necessary, and more. Yeah, I do not have an audiology degree. But I have trained ears from over 50 years as a performing and recording musician, and decades as an audio engineer / producer, some of those years in a major recording studio. I got into digital audio when it hit the market way back at the very end of the 80’s, and I have my own digital audio production studio ever since. I have been self adjusting through three sets of digital hearing aids, for about ten years now, so I think I can safely say I do have a good idea of what I am doing.

The HA software graphs are approximations, and barely that. They do not take into account crossstalk, EQ centers that are not accurate, width & overlap of EQ bands, and a host of other issues, hardware and software. Further, the REM tests themselves do not produce accurate results. I worked for two days with a hearing pro who had a REM box, and, even though we adjusted the aids in ear, and go out to try the settings in the real world, while we found some anomalies with the aids and the aids’ hardware and software, in the end, I had to reprogram my aids, using my tried and true real world sound sources. There were major differences between what the Fonix tester said was supposed to be right, and what was right in the real world, especially in regards to music fidelity.

Anybody who fits aids must wear them and listen to them, instead of relying on readouts, graphs and formulas. Even if you compensate for normal hearing, you will still be able to hear the difference between what the readouts say and what the aids are doing. “Close your eyes and use your ears- you don’t listen with your eyeballs, do you?”

Your REM observations are interesting.

As I keep saying, there is no magic bullet.

However I am (was?) hoping that REM would yield more accurate, more repeatable results than the apparently - err - ‘variable manufacturers’ software.

I agree that if you have the kit & the skills & the patience, self-tuning is likely to produce the best results.

However for 99% of users, we have to rely on the fitting software or REM software.

I am now less trusting of the fitting software … but maybe the REM software is going to be no better … !!!