Augmented Hearing: the NHS Teneo M+

Hearing aids may seem like a specialist subject. But it’s one that perhaps should be engaging all of us.

Not just because the world population as a whole is getting deafer younger. As the components and sensors in our phones become smaller and more numerous—and cheaper, many pundits believe these could eventually end up as an integral part of our bodies. Not necessarily surgically implanted—more likely temporarily housed in some body cavity. The ear canal is an ideal location.

It’s happening already with the arrival in the consumer market of “true wireless” earbuds like the Optoma Be Free 8s. Manufacturers are already beginning to add further sensors like accelerometers and thermometers to devices like these. Earbuds capable of roughly assessing your hearing profile and adjusting themselves accordingly are on the horizon.

So consumer earbuds and specialist hearing aids may well be due for a collision. The hearing aid industry, currently dominated by six main manufacturers, each with its own highly proprietary system, seems to be headed for the same shake up that transformed the computer industry in the early 80s.

I CAME TO HEARING AIDS ONLY at the end of last year. I’ve probably spent the last decade oblivious of the gradual loss of the top frequencies of my hearing (which carry a large amount of the data that makes speech intelligible) thanks to the cunning ability of the human brain to “fill in the blanks” (see box below). But it’s that same computational cunning that my new Teneo M+s are using to restore a much fuller appreciation of the soundscape around me.

The Teneo M+ has been adopted by the NHS as a standard corrective for mild to moderate hearing loss. The devices are manufactured by the German company, Sivantos, which was spun-off from Siemens Audiology Division in January of 2015. Siemens retains a stake in the new company and Sivantos continues to use Siemens branding for its products alongside its own Signia brand. Other brands associated with Sivantos and carried over from Siemens are Audio Service, Rexton, A&M, audiobene and HearUSA.

The Teneos are behind-the-ear (BTE) devices, each equipped with a pair of microphones and an output transducer (it transmits sound, but is, confusingly, usually known as a “receiver” through an ancient analogy with the telephone). The output is conveyed through a thin, barely visible translucent tube (Siemens chooses to call this a “Life Tube” for some reason) which terminates in a wider plug designed to lodge firmly in the ear canal.

From the several different optional designs of plug my audiologist settled on fitting me with a “semi-open dome” that offers minimal restriction between the ear canal and the air outside. This allows natural ingress for the lower frequencies below 1KHz that I have no trouble hearing.

This sort of dome seems to be the preferred option for mild to moderate hearing loss, although in this era of Bluetooth music direct from your phone it has its downsides, as we shall see.

The World’s a Desktop

At school we’re taught that sound is generated at a source and travels through a medium (usually air) into our ears. Simple physics. But in many respects, this picture’s far too simple. And when it comes to understanding hearing loss and how we deal with it, deeply misleading.

Outside the ear—or more accurately, outside our brain—there’s no such thing as “sound”. The current take by cognitive scientists like Donald Hoffman pictures “the world” (which includes what we see, feel, taste and smell as well as hear) as a dynamic construct inside our own heads, synthesised from a welter of internal electric stimuli triggered by external events: photons hitting our retinas, the wave-form agitation of air molecules inside our ear canals, pressures and textures on our skin and so forth.

It’s the brain that puts all this together to make a representation of the world. Hoffman likens this to a computer desktop screen display. On the desktop, meaningful symbols like files and folders simplify for us the very much more complicated workings of the machine’s internals. It makes using our computers possible: without this “hack” (as Hoffman calls it) the raw data would simply confuse us into immobility. Confusion and immobility are not conducive to evolutionary survival.

So, as with the design of a computer desktop, evolution has filtered out the deluge of information pouring in from “reality” to create a survival mechanism, a “picture of the world” that gets us through it all. I mention this because the importance of the brain can’t be overlooked in any discussion of hearing loss. For one thing, it’s our brain that disguises hearing loss from us in the first place.

Lowering the Tone

You might think that in order to deal with hearing loss that starts to slope off above 1kHz, the Teneo M+s would progressively amplify those lost frequencies to straighten the curve. Back in the days of analogue electronics that was the only approach.

The snag with this is obvious when you understand that the loss of those top frequencies can be due to irreversible physical changes in the inner ear. The parts of the ear tuned to those frequencies may have mostly stopped working.

The cochlea is a pea-sized organ of the inner ear comprising a fluid-filled tube curled up like a snail. Tiny hairs inside the tube sense the different incoming frequencies, the outmost and most vulnerable hairs responding to the highest frequencies, while the innermost hairs detect the bass tones.
In the worst case scenario, these have become “cochlea dead regions”. Analogue amplification of those top frequencies may well have to be huge in order to straighten the curve. Huge analogue amplification is bound to introduce distortion. It will also consume a lot of energy, shortening battery life. And depending on how dead those regions actually are, the hearing aid wearer may not even hear those frequencies no matter how much they’re amplified.

Modern digital hearing aids, like my Teneo M+s, are far more cunning. They can take those upper frequencies and transpose them down into the range of frequencies that the damaged ear can deal with much better. And this is where the importance of the brain function comes in.

If you did the same thing with an orchestra—told the wind section, for instance, to take everything down a couple of octaves—the result would be far from what the composer intended. But all the information, the melodic lines, would still be retained. And the harmonies, though modified, would still be essentially the same chord progressions.

Ears that fail to respond to the upper frequencies are hearing this orchestra through a low pass filter and will get a lot more information if the wind section carries out that transposition. The brain will have to do some work to make use of this new information, but adaptation of this kind is exactly what brains have evolved to do.

The official Siemens literature suggests that amplification, properly matched to the user’s audiogram, should be the first choice if the pattern of hearing loss allows this. In my own case—mild to moderate age-related hearing loss—although there’s a quite noticeable (on graphs and in real life) slope off at 1 KHz, there’s still enough residual hearing above that frequency for amplification to be the preferred option. My audiologist tells me that the Teneo M+s mix in a small amount of frequency compression, so that a portion of those top notes will have their frequencies halved or quartered, to be mapped into the region just below 1KHz where I hear well.

This combination works well, although the brain needs time to adapt. When I first got my new hearing aids I found myself puzzled by new sounds I had at first taken to be artefacts of the devices themselves. That new strange persistent twittering noise I was hearing in my office. A rogue smoke alarm? Howlround?

It turned out to be the birds outside my window, something I hadn’t heard for nearly a decade.

Inside the Teneos

A dozen or so preset programs are available for the Teneos. A choice of up to four of these, tailored to my audiogram by the audiologist, can be allocated to four program slots. The user picks any one of these four programs to suit the current environment using one of the rocker switches. These are my four:

♦  The main program is Auto. As its name implies, it’s designed to tune its profile in response to the immediate soundscape. It does a useful job dampening the howlround that can occur when output from the “receiver” feeds back into the microphones. It detects and virtually eliminates wind noise when you’re out and about. And the Auto function includes the detection and amplification of speech frequencies to help separate the human voice from the surrounding hubbub. Extraneous noise from all directions is tuned out as much as possible.

  In particularly noisy surroundings I have the option of switching to the second program, Noisy. This uses the virtual 8 microphone array (see below) to create a focus area immediately in front of me, the aural equivalent of tunnel vision. Sounds coming from behind me and from the sides are suppressed so that I can concentrate on my conversation with the person I’m facing.

♦  The program my audiologist has installed in the third slot is Loop, designed to pick up transmissions from any T-Loop system. T-Loop, sometimes called telecoil, is an audio induction system installed in many public buildings and transport vehicles. It uses one or more cables circling a designated area within which it creates a magnetic field whose modulations can be picked up by suitably equipped hearing aids. It’s a simplified, large-scale variant of NFMI (see below).

My own Loop program connects to T-Loop while still keeping the microphones open. As an optional alternative, if the user finds ambient sounds distracting, the audiologist can choose a program that mutes the mics and accepts input only from T-Loop.

  Initially, my fourth program slot was left empty. But on my second visit, once I was more familiar with the Teneos, I asked if there was a program more appropriate for listening to music. The Auto program wasn’t objectionable, but for music in a concert hall or one’s own living room, noise suppression is generally unnecessary and can create unwanted artefacts. And Auto also introduces variable gain control (VGC) that continually adjusts the overall volume, detracting from the dynamics of the music..

My audiologist accordingly installed the Music program in this fourth slot. This minimises noise cancelling, VGC and howlround protection with the aim of presenting the music with as few artifacts as possible. 

Taking Control

The size 13 battery is about half the diameter of an aspirin and will run for 11 days or more.

Physically and electronically the two Teneos are identical. It’s only after they’ve been programmed by the audiologist and fitted with the appropriate left- and right-handed Life Tubes that they become a matching pair.

Long pressing the left-hand rocker switch doesn’t actually power off the devices, just puts them into sleep mode. At night, when I take the Teneos out, I open the battery casing to cut off the juice. It’s worth noting that these zinc air batteries will continue to deplete even when not being drained by a circuit. But opening the casing helps extend their life.
Once programmed they are not quite mirror images, because the rocker switches in each device take on different functions. In my case the rocker switch on the left is used to switch up and down between the four available programs (or with a long press on either end of the rocker switch, turn both devices on or off). The rocker switch on the right controls the volume of both devices. A system of beeps and short jingles audible only to the wearer confirms each of these mode changes. For each program, the volume the audiologist has deemed the norm has a cheerful three note jingle of its own.

More expensive, smarter hearing aids aim to adjust automatically to almost any kind of soundscape, able to detect music in a concert hall or a living room, ameliorate echo in over-bright acoustics, and adapt to conversation coming from different directions. The scope of the Teneos is limited in this respect. But the ability to switch manually between these four programs (and with the help of the audiologist substitute different programs where necessary) goes a long way to making up for this.

From Ear to Ear

If the volume control on one can also change the volume on the other, you might well be wondering—I certainly was—how these two tiny devices communicate with one another. If you’re thinking of a wireless connection along the lines of Bluetooth, you’d be wrong.

Operating at a frequency of around 2.4 GHz, the same as a microwave oven, Bluetooth would boil your brain cells. Well, perhaps not quite—not at the very low power levels that Bluetooth employs for communication, around 1000th of the power of a microwave oven.

Bluetooth would still try to boil your brain, but in failing miserably lose so much power that its signal couldn’t be guaranteed to reach the opposite ear.

Hearing aids like the Teneos communicate with one another through Near-Field Magnetic Induction (NFMI), a wireless communication channel that relies on the magnetic rather than the electric component of electromagnetic radiation. Its power requirements are tiny, around a tenth of what Bluetooth needs.

NFMI, as used in the Teneos, operates in the MHz spectrum. Its reach is very much shorter than Bluetooth—think of a bubble around your head with a radius no larger than arm’s length. Exactly what you need for a body-sized private network.

One important function of this fast, through-the-skull connection is to coordinate the Teneo’s microphones. There are two of these in each hearing aid, one immediately above the rocker switch and the other at the top of the device where the Life Tube screws on. The Life Tube screw-on base includes a small vent for the microphone to listen through.

The Teneos use their NFMI connection to handle these four mics as an array of four different stereo pairs. The left and right rocker switch mics form one pair, the two Life Tube mics another. The left rocker switch mic and the right Life Tube mic are another pair, and so on. An array of eight virtual mics in all. This array gives the Teneos a very good idea about where the surrounding sounds are coming from, helping them to distinguish noise from useful information and pass on directional hints to the wearer (but see the caveat below).

Wearing and Hearing

The Teneo M+s are certified IP67. IP stands for “Ingress Protection” and these figures mean they’re impervious the ingress of dust (the 6 part of the rating) and will withstand water for 30 minutes at a depth of 1 metre (the 7 value).

So it’s puzzling to discover the official recommendation that you don’t bathe or shower with them. I’ve actually washed my hair with the Teneos in place with no ill-effects.

Except to someone standing directly behind me examining the back of my head, the Teneos are virtually invisible once tucked behind my ears with the slim Life Tubes feeding the pressure waves from the “receivers” (I’d much prefer to call them “output transducers”) directly into my ear canals.

More importantly for me, I can hardly feel they’re there and find myself occasionally reaching up to touch them with my fingertips to make sure they haven’t fallen off. (They never have.)

I was surprised to find they still fail to make their presence felt even when I’m wearing glasses. More surprised yet that I can put a pair of my Bose QuietComfort headphones over the combination of Teneos and glasses without any unwanted sense of extra pressure. It’s almost as if ears were designed to have these things snugly installed behind them.

Unfortunately, the real function of the ear flaps—pinnae, to give them their scientific name—is somewhat at odds with this positioning of the Teneos. The convolutions of the pinnae have evolved to help us detect with remarkable precision the locations of the various sounds in the space around us. If you hear a twig snap under the paw of a tiger stalking you in the jungle, it’s life-enhancingly useful to know exactly where that sound is coming from.

Typical patterns of age-related hearing loss

The higher frequencies carry most of this location information. It’s unhelpful that it’s exactly these frequencies that are now largely reaching my brain through pairs of microphones placed behind the pinnae. The electronic processing is also introducing a slight delay in the arrival time of these frequencies. It’s only a few microseconds, but triangulating with interaural time difference (ITD, the lag between the arrival of the same sound at each ear) is another very important factor in localisation and it is indeed measured in microseconds.

This helps explain my initial confusion about the twittering sound in my office. Because I couldn’t at once locate the origin as being outside my office, the brain wasn’t easily able to equate the sound with birdsong.

Location, Location, Location—this is one of the few downsides of behind the ear devices. Much more expensive hearing aids that fit entirely into the ear canal preserve natural ITD much better. And all the device form factors can ameliorate this problem with faster (but costlier) processors.

Adding Bluetooth

Many of today’s premier hearing aids pride themselves on having Bluetooth incorporated. A direct link to your iOS or Android device seems tempting, and I must confess some initial disappointment that the Teneos lacked this feature. But now I understand the technology better, I think the way the Teneo designers handle Bluetooth—outside the devices themselves—has a lot going for it.

It’s a cost option, and not a particularly cheap one. But for UK NHS users the £280ish price of the easyTek neck loop device brings the total cost of the system up to, well, £280ish. A relatively small price to pay in a market where the ticket for a similarly featured set of commercial hearing aids will probably run into several thousands.

The easyTek Bluetooth remote control for the Teneo M+

The easyTek hangs round the neck like a much more discreet version of a Lord Mayor’s Chain of Office. Its basic function is to substitute for the on-device rocker switches, so pressing on the large central button will switch between the four programs, while a pair of secondary small push buttons set into the right side control the volume. A long press on the central button turns the easyTek on or off.

Bluetooth is switched on by holding down the central button in conjunction with the upper secondary button. Once paired to a Bluetooth device like a phone the easyTek will take over as the phone’s audio output. The stream is then relayed directly into the hearing aids through the neck loop-to-Teneo NFMI link.

The easyTek is large enough to incorporate a relatively high-capacity battery, topped up daily with the microUSB charger supplied. Bluetooth streaming like this adds no drain to the tiny zinc-air batteries in the Teneos.

It was this factor that dispelled my initial disappointment at discovering the Teneos themselves aren’t Bluetooth-enabled. Bluetooth, even the so-called “Low Energy” version (BLE), soaks up ten times the juice of NFMI. Manufacturers will tell you with a straight face that the batteries in their new Bluetooth-enabled hearing aids last as long as the previous generation. This may be the case—as long as you don’t use them for Bluetooth streaming!

Like all Bluetooth devices, the tiniest hiccup can throw out the lipsync. It’s normally not hard to get it back—pause the video and/or restart the easyTek. Annoying but fixable.

No special additional program is needed for the Teneos. Once the presence of the easyTek is detected the Universal program picks up the connection. I found that, once paired to my Huawei Mate 9 and my nVidia Shield the easyTek would (mostly) automatically switch on Bluetooth and connect to either or both of these devices as soon as it sensed their Bluetooth presence.

(On the occasions when this failed I found it necessary to switch off the easyTek and then switch it on again.)

This automatic connection to both devices comes in handy when, for example, I start watching a YouTube video on my phone and decide to Chromecast it to the Shield. I was very pleasantly surprised to discover the easyTek (usually) effortlessly transfers to the Shield’s Bluetooth audio transmission.

Phone Control

The Android version of the touchControl app has a plain, uncomplicated user interface.

If all you need the easyTek for is as a handy way of controlling the Teneos without having to reach up behind your ears—and you have an Android or Apple phone—there’s a no-cost alternative. The free TouchControl app will let you switch the Teneos on and off, swap between the four programs and control the volume.

Your phone, of course, doesn’t do NFMI (although the NFC feature increasingly popular for electronic payment uses a very similar approach). So you may be wondering, as I was, how it communicates with the Teneos.

Hearing aid like the Teneos are designed to operate in the relatively narrow (in hi-fi terms) frequency range of 250Hz to 8kHz—because the science of audiology has grown up around the primary need to make speech intelligible—and the output through what I suppose we are going to have to get used to calling the “receiver” is limited accordingly. But it turns out that the tiny microphones have ideas well above their station.

They can detect ultrasound, frequencies in the region of 20kHz, the upper limit of human hearing. Your phone’s tiny loudspeaker can also operate in this range. So although you won’t be able to eavesdrop on the instructions your phone is squeaking out to the Teneos, they get the message.

If you do decide to lash out on the easyTek, there’s an app for that too. The app (just called “easyTek”) does everything the touchControl app does. But because it establishes a two-way Bluetooth communication with the easyTek device (and onward to the Teneos through the two-way NFMI link) it’s able to report on the state of the Teneos batteries, left and right, as well as the amount of juice left in the rechargeable easyTek.

The easyTek seems also to have a tone control. It’s not mentioned in the easyTek manual, and I couldn’t find any way of operating it from the physical buttons. But it appears in the easyTek Android app as a slide bar labelled SOUND BALANCE with Bass and Treble markers at each end. I discovered that pushing the slide bar all the way over to the left, Bass end subjectively improved listening to music through the easyTek. Which brings us to…

Bluetooth and the Dome Dilemma

There’s a huge catch to the use of the easyTek—or any Bluetooth in this context—which becomes apparent immediately you start using hearing aids for listening to music. But before we get on to that, we need to take a look at the nature of the domes used to terminate the Life Tubes and lodge them into the ear canal.

Three types of hearing aid dome

From top to bottom: closed, semi-open, open

Open domes became popular over the last 20 years as a perfect solution for typical age-related hearing loss like mine where only the upper frequencies need to be amplified and/or shifted. The lower frequencies that I hear perfectly well are allowed to enter the ear naturally. This preserves directionality to some extent and avoids the occlusion effect which would make my own voice sound unnaturally enclosed and boomy.

Before the 21th century, closed domes or tailored earmoulds would have been used in these circumstances. Effectively all frequencies would pass through the hearing aids, with natural sounds of all frequencies being blocked out. Closed domes are used today primarily for wearers who need correction across the whole range of frequencies.

With BTEs like mine, closed domes would move the total focus of my hearing from my ear canals to the microphones behind my ears, destroying the pinna effect and so removing a large part of the natural clues to the location of the sounds I was hearing.

As I’ve mentioned, my own domes are technically “semi-open” (see illustration), sometimes called “tulip” domes. These fit reliably and comfortably into the ear canal while still letting through the lower and mid-range frequencies. For the most part they behave like open domes.

Open (and semi-open) domes, then, are the aural equivalent of augmented reality (AR), with the hearing aids superimposing their own (upper frequency) modifications on my real-world perception. Closed domes instead offer me virtual reality (VR), a totally computer-reconstructed representation of the soundscape.

For the past couple of decades the adoption of open domes in cases like mine, augmenting rather than completely virtualising reality, has made a good deal of sense. But in recent years the application of hearing aids has been expanding. Bluetooth streaming, either built into the hearing aids or supplementing them with accessories like the easyTek, is rapidly becoming a required standard function.

This is a game changer. When the entire soundscape is being streamed into the ears electronically, AR no longer does the job properly. Only the upper frequencies are catered for. The lower frequencies, which in ordinary hearing aid use pass through open domes mostly unaltered, are now missing. A Mozart string quartet can sound as if it’s being played on a banjo.

Is this fixable? Not, it seems with currently available hearing aid technology. But if I’m right about the medical and consumer branches of the ear wear business coalescing (and this is happening now), we’re going to need dual-mode domes capable of switching programmatically between open and closed. A promising field for this may be micro electromagnetic systems (MEMS), the magic behind the “dancing mirrors” in DLP projectors.

In practice, Bluetooth streamed to the easyTek with my semi-open domes is a combination that turns out to work perfectly well for watching news on television. Movies and TV series where music plays a large part take a bit of getting used to. But if the story is gripping enough I’m happy to live with the loss of bass (which, in any case, helps to keep the dialogue intelligible). With action movies and computer games you’re definitely going to miss the booms and bangs, even with that Sound Balance slide bar pushed far over to the Bass position.

Teneo Conclusion

I was frankly amazed at how well these shrimp-sized miracles work. I’ve been a “computer guy” for nearly 40 years and have watched, cheering from the sidelines, as the technology shrank from clunky desktop machines to powerful pocketables. But these developments in audiology came as a brand new surprise.

My audiologist at North Finchley works for the High Street chain, Specsavers. The NHS has apparently delegated testing and delivery to them. I was fitted with my Teneos at the hospital, but subsequent follow-ups have all been at the Specsavers store.
It was a surprise that took a while to find its way to me. Early last year my family began to complain that I was complaining too much about their mumbling and suggested—insisted—I get my ears tested. The local doctor wrote a referral which ended up with the Audiology Department of North Finchley Memorial Hospital. Months went by (which was fine by me—I viewed the whole deal with trepidation) and it was only towards the end of last year that I got my appointment. And then, within weeks, my hearing aids.

Birdsong, the creaking floors in my house, the flutey overtones of high-flying aircraft—the Teneo M+’s augmentation of my top three octaves restored all these. And my family stopped mumbling.

And it quickly struck me that, even if my hearing were 20:20, these things would still be handy. While the Noise program doesn’t always fully deliver the goods in lively get-togethers, it certainly helps and would have been a boon back in the day when my ears were young. Being able to tune down a noisy live concert or set preferential focus on the dialogue in an over-orchestrated movie would be an advantage for anyone’s hearing, impaired or not. On top of that, there’s the advantage—thanks to the easyTek—of having the freedom to watch videos on my phone without annoying others in the room or having to put on headphones. Everyone could benefit from bionic ears like mine.

So get ready for the emergence of commodity full-featured “earwear”, offered with consumer-useful programs but also optionally tuneable by a qualified audiologist.

This discussion of the Teneo hearing aids was inspired by my friend and colleague Steve Cotterell, who runs the Facebook Website “Deaf—Not Stupid“. You’ll find a summary of this review there.
It’s not all roses. Even with the Music program installed in slot 4 I’m still not hearing the classics quite as I would like. There are some artefacts and distortions when I’m listening live or to the Yamaha RX-V679 living room loudspeaker system. Inside my QuietComfort over-the-ear headphones the Teneos work quite well (standard audiology advice does not recommend this) as long as I keep their volume down to avoid howlround.

So my music experience is still suboptimal. Tough. But I can’t help thinking that Beethoven would have killed for a pair of these.

Chris Bidmead

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  1. Michael Eacott

    Hey. Great article. I have Teneo M+ hearing aids supplied by Specsavers.

    I had problems getting the Android touchControl app to control my hearing aids and was mistaken in thinking that Bluetooth was used. I now understand that ultrasound is used for control. So I manged to get touchControl working successfully by increasing the volume control of my phone speakers and pointing them at the hearing aids. A pity that the references to pairing in the set up instructions did not state ulrasound pairing rather that let people like me infer that it is Bluetooth pairing.

    Thank you very much for helping me set up successfully.

    • Chris Bidmead

      I’m delighted that the review was useful, Michael. Months later, I’m still struck by the extraordinary technology at work in these Teneo M+s. Using ultrasound to communicate from your phone to the hearing aids is really ingenious and useful. And we can be grateful that Bluetooth isn’t used for this, as the drain on the batteries would probably mean you’d be changing them every couple of days instead of weeks.


  2. Hi,

    thanks for a great article. I have a pair of Teneo M+ with easyTek to correct my age related hearing loss at higher frequencies. As a techo geek I have also bought a Connexxlink programmer and tweak the settings myself.

    There is a solution to the problem of using open domes when streaming music. In the programming software Connnexx 8 the audiologist can change the correction profile for each program.

    So to make the streamed music sound as it should I have flattened the frequency profile, by boosting the lower end and now the sound I get when streaming music is very balanced.

    Ask your audiologist to do this for you at your next visit!

    all the best


    • Chris Bidmead

      Thanks for those helpful comments, Julian. I’ll certainly investigate that idea of getting my audiologist to boost the bass.

      I will say that since writing the Teneo M+ review I’ve been using streaming through the easyTek more and more and getting more used to the sound profile it delivers through (semi-)open domes. I’m hoping to be able to follow up with a rather more detailed review of the easyTek later this year.

  3. Thank you for this well written and informative article. It answered a lot of questions about this new to me, technology.

    • Chris Bidmead

      It was all very new to me too, Andrew. Now that ear-ware seems to be going mainstream, stand by for some more hearing aid reviews in the future.


  4. Just been supplied with a pair (NHS) through Specsavers general degradation of higher frequency sounds even though it’s early days I am highly pleased with the results and so is my wife. Made a real change to hear her in noisy places and she says that I have started speaking at a more normal volume instead of her and others not hearing me because I was afraid of speaking too loudly.

    • Chris Bidmead

      Delighted that you’re getting on well with them, Peter. One problem worrying audiologists is the very high percentage of people with disabling hearing loss who delay (as much as 10-15 years) adopting hearing aids. And of those who do become users, many (by some statistics, the majority) will reject them.

      I’m currently taking part in a European project called Evotion ( to find out what’s going on behind these statistics. Check out the link if you want to know more.


    • Update on the Teneo M +

      Hi further to my previous comment regarding the fitting of my NHS M +

      My dispenser (Specsavers) at my Doctors clinic initially did not do any adjustments to the aids saying that I needed to get my brain used to the sounds I hadn’t heard for such a long time and at least six months was mentioned.

      However, despite finding I could now hear my wife in cafes etc she was lost in the background noises such as clattering cups and saucers being stacked so, I returned to the clinic and asked if something could be done to improve it and was told that as it was NHS they were limited to functions and all that could be done was to reduce the volume to which I said that won’t help as then I would equally be losing the benefit of the higher frequency ranges which I needed.

      I went back again and said that as expected I had lost benefit and had them put back to as they came. During the last 6 months I have put up with them thinking that it would improve.

      After this time I asked my Doctor if he knew if there were any restrictions to what could be done in relating to your report and he replied, no, up to the limits of the actual hearing aids.

      Armed with your report and the information from my Doctor, I made an appointment with the clinic and again visited the dispenser.

      I have to confess that my reaction initially, which I largely dismissed trying to be fair,was that I was not being given a fair view and that possibly the private provider maybe able to do more.

      This time it was almost blatantly obvious as again there appeared to be a reticence to do more until I brought your report to their attention. I was then told that could I could have programmes but I would have to press the buttons as they wouldn’t do it automatically to which I replied, oh dear I will just have to press the buttons!

      A noisy environment was switched on and I was told I could have one for the TV and loop systems as I had spare slot.

      I initially declined the loop programme but have been back and added it as I have bluetooth headphones linked to HiFi, Chromecast and mobile which enclose hearing aids.

      I again using your report I asked about the phone app and was told oh yes to which I said that I needed a q code to set it up with which was greeted with, have you got the app and it was set up for me on my phone there and then with a is there anything else I can help you with today. My wife who was with me when we left said you have been treated like a private patient today which I have to admit certainly felt like it.

      I apologise for the length of this update but feel it may help others who may not feel they can challenge the system. As I said to my Doctor, if it is a simple as restrictions on the NHS then I know and can choose to have private provision.

      Clearly once I had challenged the dispenser I was able to have it all, which I will also feed back to my Doctor to make him aware that this is happening at their clinic and then he can choose take what action is deemed necessary.

      I trust this is helpful in all you do and thank you for your extensive report which has made so much difference.

      Kind regards and best wishes.
      Peter Flett.

      • Chris Bidmead

        Yes, I suspected that there might be pressure on NHS patients to upsell them to private services along the lines you mention.

        It’s certainly the case that the very latest privately sold hearing aids are able to offer improvements, particularly in situations like “speech in noise”. But properly programmed NHS devices can do an excellent job too.

        I’m delighted that Tested Technology has been useful in helping you through this. Many thanks, Peter, for your detailed feedback.


  5. I wonder if you can help…

    I’ve been fitted with a teneo m+ folowing an accident. They’re most helpful at the hospital, but you can only test it by talking with the audiologist, & after they adjust it you find problems in real world situations, and it’s hard to explain to them exactly what the problem is.
    Ideally I would like to be able to experiment & adjust myself, but believe that’s not possible – at least without purchasing thousands of pounds worth of equipment.
    If so, it would be really helpful if I could access documentation on what programmes are available, and what parameters they can change, so I know what to ask for.
    Though I work as a musician, I have a maths degree and have written commercial software, so don’t mind if it’s rather technical.
    At present I have 2 programmes. I’ve heard you can have up to 4 on the teneo – is that correct?
    The original one is good for listening at home or talking to one or two people, but hopeless in a noisy environment, especially with machinery or loud women’s voices and seems to amplify any echo. Music is quite impossible, on account of the anti-feedback system, I believe…Would it be reasonable to ask for a second version with anti-feedback turned off? [They kindly tried a music programme, but it was hardly any better & unuseable for playing.] My second programme is for noisy places. Much nicer sound quality – just needs a little enhancement of high frequencies. Would a second [adjusted] version of this be possible without losing the original?
    Is it possible to adjust the volume for the 2 ears independently?

    Yours hopefully!
    Alistair Logan

    • Chris Bidmead

      I’m guessing from your email address, Alistair, that you’re in the UK and I assume you’re being looked after by the NHS. If you read the comment from Julian here, you’ll see that it is possible to program the Teneos yourself. You should find that the Connexx unit he’s using can be picked up on eBay for between £250 and £300. I’m not sure where or how you get hold of the associated software (for Windows, I gather). But no complicated computer programming is involved once you know how to match the curves.

      I can’t recommend that from personal experience, but perhaps Julian can add something here. But you should be able to persuade your audiologist to help you to a proper fit.

      The “manufacturer’s first fit”, which may be what you have at the present, is supposed to be a comfortable approximation, with some attenuation to the upper frequencies (because matching the full fit at the top end will usually sound harsh to a hearing aid newcomer before the brain has had time to adjust).

      The Teneo M+ has a total of four available program slots and a dozen or so different programs that can be fitted into them. The first slot is normally “Universal”, which seems to be what you have. As you say, it includes anti-feedback and also automatic volume control (neither of these is helpful for listening to music). The second will typically be for noisy environments, focussing on sounds from the front and cancelling out surrounding noise. My own third program was set to Loop, which adds induction loop listening to the regular hearing program (or can be set by the audiologist to work with the induction loop alone). Except for the profoundly deaf, this is probably less useful than in earlier days now that digital programs have got a lot better at adjusting to the environment.

      My fourth program was set at my request to music listening. This seems to be Universal with the anti-feedback and automatic volume control switched off. It was certainly an improvement for listening to music from loudspeakers and over headphones, but I had to be careful to avoid howlround.

      Yes, any and all of these programs can be tuned by the audiologist (or you, if you have the right kit). If I’m right that you’re still using “manufacturer’s first fit” you might want to ask your audiologist for “real ear measurement”. This assessment procedure places a tiny microphone close to your eardrum so that fine adjustments can be made to match the acoustics of your individual ear canal. You may come away from this adjustment feeling that it’s a bit too “toppy”, but the result should be a rather tighter fit to your ideal that your brain will get used to.

      As to adjusting the volume of each hearing aid separately, I seem to remember that on the Teneos you can’t do this with the provided app or manually. If your ears have different hearing capability, this should be a factor your audiologist has already taken into account.

      You’ll have noticed that my responses here have been in the past tense. This is because I’ve now moved on to a pair of Oticons, as I’m participating in the Evotion Project ( I understand they’re still welcoming new participants if you’re so inclined and in the right geography.


  6. David Pannell

    I have profound hearing loss and have Teneo HP + aids what difference is there between these and tthe M+. NHS supplied I am thinking of going private and have been recommended Oticon Opn aids

    • Chris Bidmead

      David, the Teneo HP+ hearing aids are a more powerful version of the Teneo M+s, designed for moderate to profound hearing loss. My Teneo M+s are for mild to moderate hearing loss. But I believe the two models are functionally very similar.

      I don’t know enough about you to make any recommendation about going private. Having said that, my default response would be that if you’re not totally satisfied with the treatment you’re currently getting you can always go back to your GP and ask for a referral to another NHS audiologist. I was initially directed to the NHS audiological department at North Finchley Memorial Hospital, which outsources to Specsavers. I asked to be transferred to Guy’s Hospital at London Bridge, which is where I was invited to join the Evotion Project.

      The Evotion Project fitted me with a pair of Oticon Opns. As I understand it, Oticons are available on the NHS but these will be an earlier generation than the Opns. I can certainly recommend these Opns but I’m not sure the difference from my previous Teneos would be enough to justify the change if I’d had to pay the full price.

      The core problem for hearing aid users seems to me to be that we only have experience of the HAs we’ve used and find ourselves totally in the hands of audiologists with a much wider experience, a great deal of knowledge and (in at least some cases) an incentive to upsell us to high profit-margin devices.

      NHS hearing aids tend to be around one generation behind the current state of the art (but still capable of doing a damn good job). The hardware, though, is only part of the equation. The service (shaping the devices to your individual needs, expert follow-ups, battery and spares supplies) I’d argue is even more important to our ongoing welfare. And despite the well-publicised budget struggles, NHS staff in my experience perform magnificently. Compared with the private hearing aid market, the NHS is an absolute bargain (ask any of our Transatlantic cousins).


  7. I wear Teneo M+ hearing aids. Does the Easy Tek device enhance hearing in background noise. I understand they incorporate some noise cancelling technology. Excellent article.

    • Chris Bidmead

      Thanks for the compliment. I’ve learnt a lot more about hearing aids since writing that piece, but since switching to Oticon Opns I haven’t been using the easyTek.

      It’s clear to me that a device like the easyTek is a great way of incorporating Bluetooth streaming—for one thing, there’s little or no extra drain on the hearing aid batteries. But, if I understand the technology correctly, it’s not there to improve your hearing against background noise, unless we’re talking about listening to a Bluetooth stream from the TV while the family is having its typical rowdy Christmas argument.

      If you mean clearly hearing conversation with a particular person in a crowded restaurant, no. The easyTek does incorporate a couple of microphones, but they’ll never do a better job of noise cancellation than the array of four microphones in your Teneo M+s.

      It sounds as if what you’re looking for is a “remote microphone”. This is a device that the person you’re conversing with can either hold or attach to their clothing. It then transmits their speech wirelessly either to an intermediate device like the easyTek or, if the hearing aids are independently Bluetooth capable, directly to the hearing aids themselves.

      There’s a Siemens product called VoiceLink that does this in conjunction with the easyTek (for around £150) but I’m not sure if it’s still available. I hope this helps.


  8. Bob Cranfield

    Very many thanks Chris for your excellent article. It clarified many things for me. I was fitted with a pair of Teneo M+’s on the NHS just two days ago. I have found no problem keeping them in most of the time (apart from a little itchiness which can be alleviated by re-inserting the ear insert). I am suffering from “standard” age-related high frequency loss & find it very interesting to realise how many high frequency sounds I must have been missing out on. Any sharp bangs, clicks, knocks, etc are accompanied by something a bit like a hi-hat cymbal clash! I assume this will fade as my brain adjusts, but I haven’t actually found it tiring. My Specsaver audiologist has provided 3 programmes (auto, noisy environment & TV) & I’m mainly keeping the volume on mid-setting (4 presses). I was pleased to find how light and stable the fitting is, though it’s still a little fiddly to get the Lifetips properly in place. I often switch between pairs of spectacles & can still do this surprisingly easily (with just a little bit of extra care). I have also installed the TouchControl app on my phone & iPad, which could prove handy. Am now considering the EasyTek, but will probably wait to see if my Bluetooth over-the-ear phones are adequate first. Thanks again.

    • Chris Bidmead

      Delighted to hear that the Teneo M+ piece was useful, Bob. Thanks for your appreciation.

      Yes, that “cymbal clash” effect is very common with new hearing aid users. The brain has become so used to not hearing those top frequencies that now they’re being delivered at an amplitude you can register, the brain is taken by surprise. In fact, audiologists and hearing aid manufacturers will often deliberately de-tune those top frequencies to avoid complaints from users. But my view is that it’s best to get a true real ear measurement setting right from the start so that the brain has all the right data to work on.

      Your over-the-ear Bluetooth headphones will probably do everything you need. And they’ll give you the full frequency range, whereas the EasyTek loses a lot of the bass. You might need to ask your audiologist to set the Teneo M+ 4th programme slot to “Music” for use with those headphones.


  9. Thanks for a brilliant article Chris, very informative on many levels.
    I was only fitted with the teneo M+ aids yesterday at a local Specsavers (Derby NHS Trust just contracted out the service for less severe hearing loss cases). I previously had the Phonak Spirit Synergy NHS ones, one had developed a fault so had to go to Specsavers. to use their catchphrase…maybe I wish I HADN’T gone to Specsavers!
    At the moment I’m not convinced the ‘Audiologist’ has set the Teneo’s up correctly, it might just be my brain needing to reset itself for these aids, but the chap couldn’t get the software to work & wasn’t able use the specialist devices for fine tuning, I think thats the “real ear measurement” you mentioned earlier. “we’ll do it the old fashioned method”!!
    So I was having a look around the web to see what info/reviews are out there for the Teneo’s & came across your article.

    The audiologists set me up with standard & loop (with mics on) programs, he didn’t say anything about the other programs available or how many there were; even despite me telling him that I had problems with noisy situations.
    In my search I found a spec page for the Teneo’s, ( it mentions “Tinnitus therapy as standard on all Teneo aids”!, I don’t know if you or others with these aids had any experience of this feature?
    There is a page on the signia-hearing website about what the feature can do.
    Again I told the audiologist I had Tinnitus, he didn’t mention the feature.
    I downloaded the Touchcontrol app & in the ‘manual setup’ it asks “Do you use a Tinnitus Program?” so it is definielty an option.
    I also noticed in the app, when clicking on the 3 bars at the bottom (iphone version), this app also has the ‘SOUND BALANCE’ feature you mentioend for the Eaytek app, when I clicked on it it said the feature only worked with another model of aid, but when I move the slider my aids do bleep & I can hear a differecene, so maybe it does work with the Teneo’s!

    In regard to listening to music, I wondered if you had come across the ‘Mimi’ Apps – a hearing test app & a music app?
    Basically the ‘Mimi Hearing Test’ app is just that, it covers a good range of frequencies in the test & when I’ve used it mirrors what the pro’s meansured. The ‘Mimi Music’ app includes a basic hearing test, but it can use the results from the Hearing Test app, what the music app does is play the music at the adjusted frequencies, e.g. compensating for the lost ones, unfortunately there isn’t a EQ to manually tweak the frequencies, but there is ‘Mimi adjuster wheel that allows the user to go from the original sound to fully ‘mimified’, it works quite well. I’m picking up so much more of the sounds I was missing – the crisp sound of the snare & cymbals, high notes on a keyboard, plus even more of the bass. adjusting the mimi wheel confirms this.
    I’ve only used the music app with ear buds, either with my aids in or out, but not with over ears or through something like the Easytek. I wonder what it works or what it sounds like, may have to invest in the Easytek now.
    many thanks again.

    • Chris Bidmead

      You’re entitled to go back to the NHS practice that referred you to Specsavers and ask for an alternative. Either way, you should certainly insist on real ear measurement and if the kit to set this up isn’t working (I had the same problem at Guy’s) make another appointment to come back when it’s fixed. Real ear measurement is particularly important if you have problems with speech recognition in noisy surroundings.

      For noisy surroundings, you’ll also find the Teneo’s directional programmes useful. Insist on this.

      I’ve no experience with tinnitus, but, yes, the Teneo’s do have a programme for this. I believe it can play a selection of quiet sounds that ameliorate the condition.

      Thanks for the useful tip about the Mimi hearing test app. Something similar is built into the Evotion app that controls the Oticon Opn hearing aids. I’ll investigate Mimi.


  10. Interesting article. I have had a single NHS provided Teneo M+ for a month now. It was ok at first but now is whistling and crackling all the time even on volume minimum. Is this a fault. They are phoning for a review in a couple of days so obviously I will mention this. Also I only have one program available?

    • Chris Bidmead

      That whistling, Dave, as you probably know, is audio feedback. The microphones in the hearing aids are picking up the output, which should just be going to your ears.

      This shouldn’t happen. Modern hearing aids are rather good at detecting this and automatically shutting it down. You’ll still get feedback with the Teneo M+s if you’re standing close to a reflective wall, or if you cup your hands over your ears (actually, a useful way to test if the hearing aids are on and working).

      If this happens otherwise, you’ll definitely need to go back to the audiologist, who may retune the Teneos or fit different domes, or both.


  11. Hi, great read and very helpful, I have just had they Tenco M+ to replace 4year old hearing aids, I was not advised that I could have 4 programs to adjust to, are the programs automatically set or does the audiologist have to set them all for you.

    • Chris Bidmead

      Susan, the Teneo M+s do give the user access to 4 separate programs, selected by the audiologist from a possible repertoire of (I think) a couple of dozen. The audiologist will consult with you about which 4 programs to make available and will implement them accordingly. If you later feel you want to change one or more of these programs, you should feel free to go back to the audiologist for a further consultation.


  12. Interesting reading just got my new ears a few weeks ago

  13. joel montague

    what is the US price for A teneo M hearing aid each one

    • Chris Bidmead

      The review here is of the NHS version of the Teneo M+. If you’re not in the UK and are looking for a US price your best bet is probably to enquire of local vendors.


  14. Thanks for all the information. I have had these aids for about 3 years and thought the touchControl app was only to set the aids up! I only have 1 programme in the device and that has proved OK for me so far. I think I may ask the dispenser, Specsavers, to add at least the music prog. I thought originally I could adjust left/right volume but cannot find that in the app now. The spatial adjustment appears to do the same thing, if a bit heavy handed! I am going to try the BT function next.
    Many thanks again.

  15. Gill Kitchen

    Just got my new earpieces from Specsavers,Phonak Nathos Auto M, Was not shown how to fit those, and I do not know if they have even been programmed. How do they compare to the Teneo M plus, as from your excellent article, I feel these may better, although to be honest I am quite green about all of this. I have mild to moderate hearing loss. Specsavers told me they only have two kinds of aids and Phonak was the one for me. Is this right, as I feel they were rather disinterested after originally thinking I would have a private in the ear aid. Do Specsavers all have the same hearing aid.Like to know what you think. Thank you.

    • Chris Bidmead

      Gill, Phonak has an excellent reputation. I don’t know the Nathos Auto M but it is likely to be a more up-to-date product than the Teneo M+.

      More important than the hardware, though, is the programming. If you’re not sure if this has been done properly, or even done at all, you should go back to Specsavers. I assume these were supplied by Specsavers under the National Health scheme. You have a right to insist on proper programming and maintenance and this should include Real Ear Measurement.

      In my experience, Specsavers has appeared to be somewhat casual about following National Health guidelines. If they don’t comply with your wishes you have the right to take it up with the doctor who referred you to them in the first place. Ultimately, you also have the right to appeal against your referral to Specsavers and can ask to be transferred to another audiologist outfit. Whether this appeal succeeds may depend on inter-Trust NHS budget-juggling. In my own case, I pushed on through the red-tape and eventually managed to switch from Specsavers to the very excellent service at London’s Guy’s Hospital.

      I should add that Specsavers is a franchise operation, with outlets run by different individuals or companies. So my findings may not apply to your Specsavers.


  16. Roger L'Estrange

    I hope I’m not too late to ask a question, having only just found your excellent article. I use NHS Teneo M+ HAs supplied by Specsavers. I had no idea there were many possible programmes and will be going back to Specsavers. Is the Loop programme to which you refer simply reception by any ordinary induction loop or is it specific to the M+ and the easyTek neck loop? I have been given a Phonak Compilot by a friend and wonder whether this will communicate with the M+s if the latter are set to the “T” programme.

    • Chris Bidmead

      It’s never too late, Roger, although I must confess it’s some time now since I last used the Teneo M+. The Loop program is indeed the same generic Loop you find on bus transport, Post Office counters and so on. However, it’s my understanding that although the induction systems in proprietary devices like the easyTek and the Compilot use similar technology to the generic Loop, they are infuriatingly (designed to be?) incompatible with one another.

      The current hearing aid landscape reminds me of the computer landscape of the late 1970s (when we called them “micros”). Different manufacturers, each with their own operating systems and applications, all incompatible. The good news is that there are signs that unifying standards are on their way. ASHA was an early move in this direction; Bluetooth 5.2 should take us a lot further.


  17. Michael Priest

    …After 2 pairs of Teneo M over 6 years I was in May provided with a pair of NHS Signia Contrast S+, these being the latest appliance dispensed to NHS contract by our local branch of Specsavers (they have provided my hearing aids, initially, privately,in 2011, since 2012 to nhs specification).

    Firstly my latest experience with Contrast S+ in comparison with Teneo M.

    …I’m nearly 77, my hearing loss in both ears has been gradual over the last 10+ years. The most recent Teneo M pair supplied in 2019 were, I was aware, less effective, subjectively in 2022 than in 2019. There had been an update maybe late 2020 to allow for clinical variation, which included earwax microsuction,but when I scheduled my update in May last I was much aware of the need for enhancement.

    My hearing was retested and I was offered Signia Contrast S+ as the latest NHS supply option which I duly accepted and was dispensed accordingly at the consultation.

    The supply terms were as previously. Two aids provided and after-care to include return/review visits, battery replacements as required periodic replacement of tubing and ear buds.Any repair or replacement required to be under NHS unless neligence admitted eg careless loss or damage to one or both aids…

    They have facilty for 6 programmes. I have those installed into my left (dominant ear) aid with a varying audible signal for each, they offer different characteristics which I can adapt by selecting from the dip switch on the earpiece. The right dip switch controls volume.

    The app installed on my Android phone (similar to the Teneo M but tuned to the Signia Contrast S+) provides external control, but like the previous Teneo app selection I have noticed that the sound quality is slightly different when under control of the app. So this effectively gives me a selection of 12 options, enough to cover most encountered audio environments.

    I guess the Signia Contrast S+ has been engineered to meet a price consideration, probably the lowest that Specsavers can negotiate with their massive purchasing leverage.

    Does it work, meet the criteria? It’s ok by me, I can hear, I could probably improve subjective quality in varying surroundings by spending a £K or two. I’ve learned to be selective in creating how I cope in different circumstances and it doesn’t always work out. Whether that is the aids or just me I’ll probably never find out, but I doubt if I could really explore fully any advantages that an expensive private aid may confer without speculating.

    Meanwhile I stretch the capabilities of Signia Contrast S+ as I must.

    • Chris Bidmead

      Thanks for those thoughts, Michael. I’ve taken the liberty of trimming your rather long comment down a bit.

      Yes, you raise an interesting point — with all these various and expensive high end hearing aids coming onto the market, how does one realistically make a meaningful choice? Some things are clear to me: today’s hearing aids, whether NHS or private, are a huge improvement on those of ten years ago — and they’re still getting better. Also that the BTE (behind the ear) models favoured by the NHS don’t do as good a job as the RIC (receiver in the ear) design characteristic of most privately sold hearing aids.

      The former have the output transducer embedded in the device and relay the output through a narrow tube to the ear. RICs place the microphone directly in the ear, a more expensive arrangement to manufacturer. I believe that conveying sound down the tube obfuscates important phase information the brain needs to determine the location of the sound’s origin, information that RICs preserve.

      Other than that, how does one distinguish between an NHS hearing aid (free of charge but £65 if you lose it) and a privately sold device that might cost orders of magnitude more? I’m very much inclined to your point of view: stick with what you’ve got and make the most of it.


  18. Richard Price

    It’s rather a while since your article was written but I too have NHS Teneo M+’s supplied by Specsavers. Being an electronic engineer by training and technically interested in audio, I was quite well up on the technology and the science of hearing, but your excellent article filled in a lot more details. I’ve found the Teneo’s very good, comfortable to wear (with glasses) and easy to get used to. I had what I assume was real ear testing when I was originally fitted, and again when I went in for a review and addition of extra programs. However I’m now beginning to find I need more amplification and don’t hear well in company. I find I’m selecting the TV program because it boosts the overall volume as well as enhancing the higher frequencies, but it’s still a struggle. I’ve found my excellent over the ear headphones (mine are still wired) work very well with the aids and improve hearing and clarity particularly on programmes where people with strong accents are talking (such as Shetland), or sound recording quality is poor. Even before I had HAs I found the headphones enhanced the quality of my hearing of the TV, particularly clarity and bandwidth. I’m now wondering whether the higher power aids mentioned in comments above would be a better solution for me now, so I’m very grateful for all the information this has provided so I can go in well armed! Thanks.

    • I’m assuming, Richard, that your Specsavers Teneo HAs were supplied by the NHS. If so, you should be able to rely on them for maintenance and updates.

      You don’t say how long you’ve had the Teneos. Obviously, I can’t give you specific advice, except to say if you feel your hearing has changed since your original fitting it’s time you asked for a retest and, if necessary, a refit and possibly even an upgrade to newer devices.

      Do please let us know how you get on with this.


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