Remove hearing aids before panoramic dental x-ray?

September 2019 I had a 3D scan that was required for a root canal procedure the following week. (Prescott Arizona)

I was wearing a pair of Signia 7Nx. It was after that the left receiver in the hearing aids was just static like noise. They knew beforehand I was wearing hearing aids.

I never cared for the Signia 7Nx, using as a spare now. I currently have Phonak Marvel P90 provided by the VA, they would be perfect if it wasn’t for the flawed app that never lets you retain a setting and only defaults to Auto. Dr Cliff in a response to me stated this spring there would be an update to correct this. I’ll believe that when I see it!

@Emile030 said:

I am in contact with Phonak sorting out and discussing radiation issues. Do hope to post more about it after awaiting there expert opinions.

Phonak states on page 81 in the Paradise manual to remove and store the aids outside the exam room before undergoing medical or dental examination with X-ray.

Sounds like an expert opinion to me.

Jim

@w0pjk1 Thanks for your info. May I additionaly ask how old your Signia’s 7Nx where. They where brought to market in 2017 I know. I live in the Netherlands and you get 5 years guarantee at most Audiciens over here.

I spoke to two Siemens guys of the CT support department to ask about this matter by telephone. They could not find a reason why this should happen… They looked over the support instruction manuals for engineers also and were also surprised about this sentence. Could not find scientific evidence. I will write an official letter now to Siemens to find out more. Siemens is producing medical X-ray devices as well as Hearing Aids to great luck…

From Phonak I still have no hard evidence, only also the suggestion that X- rays could probably not hurt, but Magnetic fields as in MRI of course could damage.

In almost every HA manual, not only Phonak and Siemens, it says you have to take them out. But untill now the HA engineers and X- ray manufacturers could not tell me why and say to me this is a kind of security sentence in the manual.

X- ray’s are ionising and that’s why they can have an effect of aging on substances. But that can hardly explain why a HA would go bad if you do not expose them for ages. There would be no substantial Magnetic Field induction either, is what they tell me. Very strange to me so that’s why I will keep searching on this topic…
I hope someone with damage on HA from the Netherlands is responding as this would make the case more interesting for f.i. television reportage.

I already contacted the Dutch board of medical devices, who controls the national medical device system (kind of FDA), to ask for an explanation. They will make an official report to Phonak but cannot change the facturers manual, but they also cannot see any explanation. By the way the scientific explanation for the manufacturers is not part of their job.

The last message I received is from Phonak Netherlands, in response to questions to Phonak Switzerland, Phonak US and Phonak Netherlands (Translation from Dutch to English by Google): “In response to your submitted messages (English and German) I would like to inform you the following. As you have probably learned before, wearing hearing aids while taking an X-ray is not recommended. This is also something that is mentioned in our instructions for use. In the meantime, I have also submitted a question to our head office to find out why this is exactly and whether this can be explained in more detail. This is because X-ray is not an MRI and, to my knowledge, does not use magnetic fields. Unfortunately I have not had any feedback on this yet. As soon as this is the case, I will contact you again as soon as possible.”

@JBC Thanks Jim for reporting page 81. As you can read in this topic we discussed this sentence before. It is not only Phonak Paradise who states this in the manual. Most manufacturers do.

I am working out the scientific explanation for this. Manuals always state behaviours for the users as pull the plug of your television out of the socket , wear a grounded bracelet or danger X-rays, do not enter.
I was working full time in last mentioned spaces professionaly with my Resounds as was my biggest friend colleague with his Phonak’s untill some years ago and never experienced any problems. (Retired now) Nor have we ever been advised by our Siemens and Philips application support staff in academical hospitals to take them off because of X-ray. Also our medical radiology trade association I never heard talking about this issue! But I will contact them too and report over here in this topic.

Thanks for your additional info.
FYI: Phonak (which was not your Siemens HA, I know) is now discussing with me that what is in the manual thrue or not is not to be taken out. As I cannot change this kind of behaviour I will see if more more powerful media, if any, can influence this. Because I feel insulted as an x-ray professional.
In my country, it is against the law to make claims with regard to medical equipment and treatment that are not legally and conclusively proven.

Could it be that it’s not the ionizing radiation itself causing the damage, but the high electromagnetic flux generated by the x-ray apparatus as a whole?

There must be capacitors with high voltages, coils to drive the x-ray emitter (CRT?), etc that could - in close proximity - generate a magnetic flux strong enough to damage hearing aids.

But , Jim, I’m an old codger, not an electrical engineer!

Thanks for your suggestion. You sureley have a point over there. It is indeed what I also thought about. Only thing is that most of these technical parts are not in the same room as the patiënt is.
That’s why I asked my questions not only to HA and x- ray device sellers but also to x- ray departments in hospitals. And now I am in contact with the Dutch medical physics association to find out more about it.
We’ll see…

Thank you for your interest SpudGunner.
The answer is no. I am working on this since 7th of January when mazda4me started this for me interesting topic.

It’s like politics, lots of fake news and hidden information. But I still have questions pending to see if there is any clarity as to why it is in instructions for use if the scientists cannot provide scientific evidence why it should be harmful.

Untill now even the hearing aid manufacturers tell me x-rays should not be harmfull for their Hearing Aids. But if you aks them why it is in their usersmanual they get lost in diffuse talk and cannot give any scientific information.

What comes nearest in my thoughts also is the suggestion you stated about magnetic field induction in the neighbourhoud although this seems rather unlikely too. Approved medical equipment should be shielded and protected if there could be any chance of harmfull effects.

Radiology departments cannot take the risk of any situation in where people with cardiac devices, ventilated patients and monitoring equipment and explosive gasses are used etc. are exposed to unknown effects of the x-ray emitting equipment. These rooms should be as save as possibel to everything.

But that’s why I, after asking HA factories and x-ray equipment factories also asked in academical radiology departmentes now asked the National Dutch Medical Physics group to inform me. But they did not answer yet.

Untill now I did not find any specialist who told me x- rays could be harmfull for Haering Aids
apart from two wearers at this forum who have experienced their devices stopping / malfunctioning after X-ray examination, whereby even the manufacturers indicate that this must be a coincidence.

Zo lets wait a bit on the reaction of the medical physics group. Then I am done with it. Fake news will always be in our world and I can live with that as it is as it is. If one is afraid of anything, do your best to avoid it or go to the doctor or someone els who can help you.

@Emile030 said:

Untill now even the hearing aid manufacturers tell me x-rays should not be harmfull for their Hearing Aids. But if you aks them why it is in their usersmanual they get lost in diffuse talk and cannot give any scientific information.

Thanks for your efforts to find the answer. I suspect that the actuaries and lawyers have gotten together and decided to include a warning because:

1. X-rays are becoming more ubiquitous for security reasons, and

2. Chip foundries are using smaller and smaller architecture (Oticon’s new Polaris chip is 28nm - small for HAs, I’ve read).

Still, I am convinced that accidental leakage of strong EM flux fields is a real threat to some electronic devices - hearing aids among them.

I may be frightened of this Phantom EM/RF Monster for no good reason, but every time I cook something in my microwave oven, I wonder.

À bientôt
Spud

I asked this question to the Dutch Institute of Clinical Physics, here is their answer:

Dear Mr. XXXXX

I submitted your question to our Radiation Hygiene Committee and received the following answer:

From a physical point of view we cannot imagine that a hearing aid can break, but we cannot give individual advice and the patient should consult his / her audiologist / hearing care professional for this. We can say that with regard to the image quality a hearing aid may affect when an image is taken in this region. We recommend that you discuss this with the appropriate physician or employee in the imaging department conducting the examination.

Apparently, the hearing aids often cause shadows and other artifacts when worn during a panoramic dental X-ray. Nothing to do with frying the devices.

At least that’s my understanding…

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[EDIT 22April/'21: I had a dentist appointment yesterday and I asked him about hearing aids and X-ray radiation. He confirmed that wearing hearing aids during panoramic X-rays can cause imaging problems, but he’s never heard of the hearing devices being damaged.

DrMike is well-read (i.e., he keeps current with journals and scholarly articles). I trust what he’s telling me …]

My wonderful Veterans’ Affairs Canada has just approved me for an Oticon EduMic.

I was reading the online manual, which says this:

I don’t see why/how the HAs themselves would be any less susceptible to damage than the EduMic.

FYI

Long ago I involved in this topic and some time ago I got some new information from the Dutch productmanager from Signia (WS Audiology: Signia and Sivantos). I would like to add it here to inform you about my research. This is what I got from him (thanks to Google translate for the English translation):
It appears that X-ray examination can affect the fine structures of NVM memory circuits. This is the permanent memory in hearing aids. Tests are done with the hearing aids and X-rays with a power of 100kV/100mGy. More than 100kV can potentially damage the chips, hence the warning in the manual for hearing aids. Should the hearing aids be damaged, this will have no further consequences for the safety or health of the hearing aid user. If damage occurs, the hearing aid may no longer meet the requirements for processing and processing the sound, causing the hearing aid user to notice that the hearing aid is not functioning.
(fyi Panoramic dental x- ray is far beneath 100kV)

Speaking as an EE, with a Masters in microelectronics technology, and a career designing chips, I can assure you that exposure of memory chips (Eprom, EEprom, and Flash) to X rays can cause the miniscule amounts of stored charge inside them to dissipate.

Potentially blanking out or just corrupting the data inside them. Firmware, custom programs etc. Even if not immediately damaged, weakened and liable to corrupt much sooner than otherwise. Why take the risk ? Why fixated on keeping your aids in during any such procedure ?

Zap such a memory chip enough, to corrupt the bootloader, and the HA manufacturer will not be able to recover it. Except maybe by de-soldering it. Which is hardly a practical possibility.

CT scans, or other significant doses from medical X rays, have the potential to zap the memory chips. Even if they don’t at first, they can weaken the charge inside, sometimes only a few electrons.

I have done that before, to blank out otherwise on-time programmable processors or memory chips. which were plastic encapsulated, not ceramic with a window in them to zap them with UV light.

MRI’s are different, no ionizing radiation but extreme magnetic and RF fields. Also very capable of destroying electronic circuitry by quite different mechanisms…

No competent radiologist would allow you anywhere near an MRI machine with hearing aids in your ears. I have had three now, and they were even concerned as to whether I might have some tattoos or even piercings (no). Apparently even some tattoo ink can heat up in that environment and cause skin burns. I do have some bits of titanium inside my ears which they knew about, and knew were not going to be a problem.

Knowing that I have also worked in an industrial environment, potentially exposed to shards of metal getting into my eyes, happened once but extracted, they were also concerned about that, as well as the fact that I eat game, shot with steel shot, some of which might still be inside my bowels. But head MRIs only, so they decided not to CT me first to look out for that.

Frankly, the HA manufacturers do know, when they caution against allowing their aids to be exposed to e.g. medical X-rays. Of which CT scans are quite a powerful variety. Why on earth would you do so, for no good reason ?

Luggage screening at airports etc. is at a far lower level, nothing too much to worry about with that.