Cochlear Implant: Best Technology Myth

[soutthpaw]

I have seen several people post claiming that a certain Cochlear Implant manufacturer has the best or most advanced technology. I would clan this is totally unsupported fanaticism and no real facts/research/data to back it up. Rather I think it's more accurate to state that each company has developed different approaches to programming and advancing their device capabilities.
FURTHERMORE, I BELIEVE THE CURRENT HARDWARE AND SOFTWARE OF ALL THREE COMPANIES EXCEEDS THE SKILL OF MOST AUDIOLOGISTS AN
ABILITIES AND SKILL SET.
I have been reading a good clinical text titled "Programming Cochlear Implants" 2nd edition by Wolfe and Schafer. Combined with my own experiences I see that even skilled audiologists don't always understand or have the best explanations of the various modes and strategies.
It is quite obvious that there is a lot of growing room in the Nucleus 6 processor and the implants themselves as well as the software is easily expanded with improved functions and feature sets.
I am honestly not a fanboy on any specific brand but as I have the cochlear brand that is where my experience lies. I also think if someone is getting a CI and the surgeon does not offer all 3 brand as choices the surgeon should be able to justify went he/she does not offer a specific brand. They should also be able to cite research, personal experience with the device and working with recipients of that brand to support their argument.

There is a lot of misleading info posted on claimed CI comparison websites that looks great on paper but doesn't really apply in real world.
One example is the max speed or PPS. Yet all the research show most recipients do better with speeds between 500-2000pps Certain brand seem to do better at slower speeds than others. I had 2400pps for years just got changed to 1200 and had instant/drastic improvement in clarity of speech and music. Not to mention I got this on a device 2 generation newer. But years ago a highly experienced audiologist thought I was doing better at a faster rate.
Also the IDR numbers don't correlate across brand as Cochlear uses a different definition called IIDR. Also an equally important factor is the Electrical Unit range that the signal is output to the processor. This is not addressed in most comparisons. It's also not measured in Db. It's measured in microvolts. It's the Electrical range between your T and C levels in your map. Applies to all 3 brands The larger this range the less your IDR has to be composed to transmit sound to the implant.


I would encourage everyone to choose their wording better. If you CLAIM something is more advanced then provide evidence to support it. Otherwise claim it's different and the difference results in what you feel is better whatever...

So here is where we can discuss differences, experiences, ask questions about the technical aspects of the various brand devices and programming. Let's not make this an argument but rather an information thread for all.

 

[Condor1970]

I agree. The small variances in each companies latest technology, and the way they interact with the perception of the human brain makes this a rather moot subject when claims are made between the technology of the three brand names.

When it comes to processor technology, each company has a tendency to use the absolute latest in chip design when they come out with a new processor. Thus, they have a tendency to leap frog each other every year or so. The only way to really say that one is better than another, is to get the newest processor between all three companies. Keep in mind, the progression of technology is actually not that great as far as sound quality goes. I think on a technical level is N6 the absolute latest processor chip technology currently available, as it is the newest design? As least that's what I read. Along with the fact that they have implants with the most electrodes for signals to be sent to the brain. Could be wrong though, and it really doesn't matter either. In theory, if the same implant could be used for AB, Med-El, and Cochlear, I doubt much difference in sound quality would be noticed between their latest processors.

The biggest jump in technology you will notice is if you upgrade from one processor like the Cochlear Freedom, and jump all the way up to a Nucleus 6, which is two steps up in technology, and has the most features. Many say they notice an increase in sound quality from N5 to N6, but not as much as Freedom to N6 for example.

Keep in mind also, the brain is an analog biological computer, and the way it perceives things from a digital input can vary greatly. On ocassion, there have been users who say the older processors sound just as good as the new ones. Mainly because in some cases the brain doesn't know any different. Usually a difference is noted though.



Oh, and when it comes to the surgeons preferring a certain brand name. My daughters ENT said he at one time used all three companies (years ago). I asked why he only does Cochlear now. He stated to me he had the best experience working with that company, the best warranty for their products, and also he kind of explained his reasoning behind preferring the seemingly minimal 1% difference in implant failure rate. He basically put it like this. He does 2-4 new implants per month. So, basically anywhere from 24-48 per year. So, to make it understandable let's use a round number of 50. Now in theory let's say he is a busy doctor, and the failure rate is only a difference between 1% and 2% respectively. In theory he will need to do 1 implant replacement per year instead of only 1 every 2 years.

Now in theory, as time goes on over the years, he sees a slow but progressive increase in the number of implant replacements due to failure rate as his patient load has increased as well. He basically said that it has gotten to the point now that he does a replacement every couple months (many patients from other doctors too), since he's been doing this since the early 90's. He has been able to minimize the need for this by about half, since he switched to using Cochlear brand only about 8 years ago. He saw an increase in replacements for several years, but now is subsiding. Basically, it frees up that daily schedule for him to do surgery that is deemed more important than just doing implant replacements.

It may not seem like a lot, but if he can delegate his time to give a new patient a new implant, instead of a replacement for an old patient while the new patient needs to wait, then it is obviously what he prefers.

 

[BleedingPurist]

There is a lot of misleading info posted on claimed CI comparison websites that looks great on paper but doesn't really apply in real world.
One example is the max speed or PPS. Yet all the research show most recipients do better with speeds between 500-2000pps Certain brand seem to do better at slower speeds than others. I had 2400pps for years just got changed to 1200 and had instant/drastic improvement in clarity of speech and music. Not to mention I got this on a device 2 generation newer. But years ago a highly experienced audiologist thought I was doing better at a faster rate.
Also the IDR numbers don't correlate across brand as Cochlear uses a different definition called IIDR. Also an equally important factor is the Electrical Unit range that the signal is output to the processor. This is not addressed in most comparisons. It's also not measured in Db. It's measured in microvolts. It's the Electrical range between your T and C levels in your map. Applies to all 3 brands The larger this range the less your IDR has to be composed to transmit sound to the implant.

The higher PPS rates allow for more complex strategies. Rather than directly stimulating the recipient at those high rates, it makes strategies possible like Fidelity 120 as well as strategies that are in development. Med El and AB both have multiple power sources that require those higher PPS rates to maintain a consistent rate that can be received by the recipient.

IDR does correlate across brands. Instantaneous Input Dynamic Ratio is a marketing term... kind of like "Retina Display." IDR is measured in decibels heard in an instant. Instantaneous is used to describe how the 45 db window moves up and down, but that is precisely how IDR works. The window is established by the loudest sound at any moment. It just isn't a parameter that is re-definable.

I'm inclined to agree on the recent overstating of best technology. Scientifically, this has not been shown to be the case with any manufacturer.

 

[soutthpaw]

Actually the loudest sound at the moment does not set the IIDR which can be set from 9 to 84bd and that is then modified by the Sensitivity setting in both manual control and using ASC. 84-9 is 75db window. The default is floor @ 25db at sensitivity #12. Pg 66/7 if referenced earlier text.

For example I can adjust my threshold lowest dbl. using sensitivity to block out the ticking clock and computer fan or to hear those quiet noises.
Also the other sound processing strategies like ADRO, SNR, Whisper etc effect how sound inside and outside the window are modified. I'm going to make a separate thread and hopefully explain each of those better than any audiologist ever explained them to me

 

[mijo]

wow, could not agree more with soutthpaw.

I have been reading over so much to try to make a brand decision and find it disconcerting that so much of the info seems to just be marketing.

Some examples:
I remember reading about how important the number of electrodes are, but then notice that many people intentionally turn some of them off to achieve their desired experience.
I remember reading about how parallel electrode powering is so important but then read that not only is the parallel driving only for a small subset of electrodes, but that many people have even chosen to use a sequential mode on an implant that supports parallel.
I remember reading how electrodes too near each other cause crossover distortion, but then calculated the electrode spacing and found that one brand that claims its spacing avoids this problem not only makes implants that are nearly identical in spacing when compared to the other (difference of 0.03mm on a gap that is around 0.90mm), but also don't address whether driving neighboring electrodes in parallel might cause even more crossover than driving slightly closer ones only sequentially.

From a theory standpoint, I can definitely see the possibility of higher stimulation rate and parallel driving being potentially beneficial to reproducing stimulation that more closely mimics music perception. Anecdotally, I have seen much more positive music stories from AB folks than from CA folks, though it is very difficult to get an accurate take as the forums are sponsored by the manufacturers and discussion that includes other brands is essentially prohibited (I wouldnt be surprised if bad stories are even also suppressed).

I would love to see a thread that tries to address all this technology more matter of factly. Sounds like I also need to buy that programming book.

 

[BleedingPurist]

I remember reading about how parallel electrode powering is so important but then read that not only is the parallel driving only for a small subset of electrodes, but that many people have even chosen to use a sequential mode on an implant that supports parallel.

Hmm, I've been around for a while now and very much on top of the technology. At no point has there been any emphasis on parallel electrode stimulation as being important. The emphasis has been on having the options available to you as an individual to match your needs. While so many people have chosen to use sequential stimulation, so many people have also chosen parallel stimulation. For every person that swears by sequential, you'll have someone that demands parallel stimulation.

Parallel stimulation is much more full sounding and could be argued as being more natural sounding. For some people, this is exactly what they get from it while still others will find sequential stimulation to be their particular match. The truth is: there is no one size fits all when it comes to strategies, which is why having an array of them available to you is a good consideration to have in making your choice of an internal implant. Both AB and Med El offer this.

www.cochlearimplanthelp.com has the most up-to-date and obective information available.

 

[mijo]

Thanks purist. If I understand correctly, current steering cant be done without parallel driving. Current steering is the basis for virtual channels and the whole claim that that technology is 'superior' for more complex hearing environments (eg speech in noise and music/pitch perception, etc). (To be fair, there are studies that claim virtual channels can be achieved using sequential driving as well, but not only are the results of that unclear, its not supported in currently available solutions anyway--may not even be theoretically possible given hardware limitations).
Even besides that specific use of parallel driving, one of the touted benefits has clearly been multiple drivers (which allow parallel firing in the first place).
This is what I meant by the claim that it is important.
To be honest, if a sequential AB recipient can hear music great, it seems there should be absolutely no reason a sequential CA recipient couldnt also have the same experience (perhaps even a better one given the additional electrodes). This makes the experiences I've been reading about confusing. I am still trying to reconcile that.
IMHO, the real decision comes down to reliability/warranty vs potential complexity (which may or may not lead to better perception if used properly. )

 

[BleedingPurist]

Thanks purist. If I understand correctly, current steering cant be done without parallel driving. Current steering is the basis for virtual channels and the whole claim that that technology is 'superior' for more complex hearing environments (eg speech in noise and music/pitch perception, etc). (To be fair, there are studies that claim virtual channels can be achieved using sequential driving as well, but not only are the results of that unclear, its not supported in currently available solutions anyway--may not even be theoretically possible given hardware limitations).
Even besides that specific use of parallel driving, one of the touted benefits has clearly been multiple drivers (which allow parallel firing in the first place).
This is what I meant by the claim that it is important.
To be honest, if a sequential AB recipient can hear music great, it seems there should be absolutely no reason a sequential CA recipient couldnt also have the same experience (perhaps even a better one given the additional electrodes). This makes the experiences I've been reading about confusing. I am still trying to reconcile that.
IMHO, the real decision comes down to reliability/warranty vs potential complexity (which may or may not lead to better perception if used properly. )

There are 4 levels of stimulation to keep in mind with AB, to keep it simple. Sequential Hi Res is one electrode at a time. That is a total of 16 channels. Parallel/Paired Hi Res is two electrodes at a time with a total of 16 channels. Sequential Fidelity 120 is a combination of one electrode at a time (when the channel comes directly off a single electrode) and two electrodes a time (when the channel is between electrodes) that make up a total of 120 channels. Paired Fidelity 120 is 2 electrodes at a time or 4 electrodes a time to make up the total of 120 channels.

Cochlear's ACE strategy works with a total of 24 (or 22) electrodes/channels with a range of 8 of those electrodes used per pulse depending on the most prominent sound at the moment. It is closest to AB's Hi Res Sequential in terms of number of channels with a couple of additional channels, but without constant full array stimulation with every pulse. A CA user might have near the same experience as a Hi Res S user, but you have to keep in mind that most Hi Res S users moved on to Fidelity 120 S and found it to be night and day in terms of music resolution.

 

[mijo]

There are 4 levels of stimulation to keep in mind with AB, to keep it simple. Sequential Hi Res is one electrode at a time. That is a total of 16 channels. Parallel/Paired Hi Res is two electrodes at a time with a total of 16 channels. Sequential Fidelity 120 is a combination of one electrode at a time (when the channel comes directly off a single electrode) and two electrodes a time (when the channel is between electrodes) that make up a total of 120 channels. Paired Fidelity 120 is 2 electrodes at a time or 4 electrodes a time to make up the total of 120 channels.

Cochlear's ACE strategy works with a total of 24 (or 22) electrodes/channels with a range of 8 of those electrodes used per pulse depending on the most prominent sound at the moment. It is closest to AB's Hi Res Sequential in terms of number of channels with a couple of additional channels, but without constant full array stimulation with every pulse. A CA user might have near the same experience as a Hi Res S user, but you have to keep in mind that most Hi Res S users moved on to Fidelity 120 S and found it to be night and day in terms of music resolution.

Wow, thanks a lot for that. The specifics of this technology is something i've not been able to find in my searches. Especially helpful to understand that AB's S is in reference to channels (virtual or otherwise) and thus can still mean a pair of electrodes being driven in parallel in some cases. Does it literally sequence through all 120 channels then, or only stick to the frequencies being detected?
Interestingly, I read a study the other day about users who had moved from hires to hires120 and although i've heard many talk about the stark difference between the two, the study indicated that there was little change in the pleasure level between the two for music.

 

[BleedingPurist]

Wow, thanks a lot for that. The specifics of this technology is something i've not been able to find in my searches. Especially helpful to understand that AB's S is in reference to channels (virtual or otherwise) and thus can still mean a pair of electrodes being driven in parallel in some cases. Does it literally sequence through all 120 channels then, or only stick to the frequencies being detected?

I'm not completely sure on that, though I have understood that it sequences through all of the channels. Yes, sequential within Fidelity 120 still uses paired firing, but the channel created is a single channel. In the paired strategies, two channels are being received at the same time.

Regarding the comment on the study results, I suppose it depends on the study. Some people take longer to acclimate to a new type of strategy, so they can be initially resistant until they fully settle in. The same person rating "no change" or worse" could completely reverse course a year later, especially when hearing through their older strategy to compare.

 

[mijo]

Ok, I found AB's document that describes HiRes120 (it also includes a reference to that study I'd mentioned. And I agree that these perception measurements are somewhat problematic).
Anyway, in reading the description, this algorithm does not sequence through all 120 channels 'each time around'. Instead, it sequences through each pair of electrodes and chooses only the highest spectral power that exists for that electrode pair (out of a possible 8), and then adjusts (steers) the current to achieve that particular virtual channel. In other words, if you can envision this, it acts like a series of 15 'sliding' electrodes that are able to move inside your cochlea. Or maybe a better way to imagine it is like having 120 electrodes, but only 15 of which can fire on any one cycle through the electrodes. It would be interesting to understand how often each virtual channel is used in different environments. Especially whether there is ever any phase locking between a heard frequency and the cycle rate of the device.

 

[mijo]

And one irony of this virtual channel approach is that it debunks the claim that there will be interference from electrodes that are too close together, since the whole idea of this approach is to create an electrode set (albeit virtual) that that can be arbitrarily close together (as close as 1/8 of the distance between the physical electrodes). I wonder whether the algorithm would choose to discard the highest spectral band if it ends up being too 'close' to the neighboring pair's highest spectral band. If not, AB's higher pps could actually be a detriment. Fascinating stuff.

 

[BleedingPurist]

Ok, I found AB's document that describes HiRes120 (it also includes a reference to that study I'd mentioned. And I agree that these perception measurements are somewhat problematic).
Anyway, in reading the description, this algorithm does not sequence through all 120 channels 'each time around'. Instead, it sequences through each pair of electrodes and chooses only the highest spectral power that exists for that electrode pair (out of a possible 8), and then adjusts (steers) the current to achieve that particular virtual channel. In other words, if you can envision this, it acts like a series of 15 'sliding' electrodes that are able to move inside your cochlea. Or maybe a better way to imagine it is like having 120 electrodes, but only 15 of which can fire on any one cycle through the electrodes. It would be interesting to understand how often each virtual channel is used in different environments. Especially whether there is ever any phase locking between a heard frequency and the cycle rate of the device.

The process you are describing is very, very, very fast. There is no consideration towards how often each virtual channel is used in different environments. You experience it as 120 channels or virtual electrodes. In short, you are just hearing it all. Different environments come into play if you are using ClearVoice, which deliberately filters out steady state noise and reduces talker babble and does require the use of Fidelity 120.

 

[BleedingPurist]

And one irony of this virtual channel approach is that it debunks the claim that there will be interference from electrodes that are too close together, since the whole idea of this approach is to create an electrode set (albeit virtual) that that can be arbitrarily close together (as close as 1/8 of the distance between the physical electrodes). I wonder whether the algorithm would choose to discard the highest spectral band if it ends up being too 'close' to the neighboring pair's highest spectral band. If not, AB's higher pps could actually be a detriment. Fascinating stuff.

Considering AB's higher PPS to be a detriment is like considering the ability of a sports car to reach 160 mph. It can go as slow or as fast as you may need.

Interference is more likely if you are using Paired Virtual Channels, but not every user experiences issues with this. It really is ultimately down to individual physiology and response.

I've used both. The channel interaction I experience with Paired Fidelity 120 is experienced as very low level static that turns unnoticeable with time. Not everyone will experience this. Sequential is markedly cleaner sounding in my experience. You have die hard users of both types of strategies who have tried both.

 

[mijo]

Considering AB's higher PPS to be a detriment is like considering the ability of a sports car to reach 160 mph. It can go as slow or as fast as you may need.

Interference is more likely if you are using Paired Virtual Channels, but not every user experiences issues with this. It really is ultimately down to individual physiology and response.

I've used both. The channel interaction I experience with Paired Fidelity 120 is experienced as very low level static that turns unnoticeable with time. Not everyone will experience this. Sequential is markedly cleaner sounding in my experience. You have die hard users of both types of strategies who have tried both.

There is a claim that CA's electrodes are too close together and thus create a crossover effect. However, CA's device cannot drive electrodes in parallel. Yet in 120, you can have the same electrode fired in subsequent pulses (and if you count virtual channels, you can have two channels MUCH closer together than CA ever could) and at a potentially much higher PPS. So all I was saying is its inconsistent to claim a crossover in the CA case, but not in the AB case. This is not a criticism of the technology, just trying to understand the claims that get thrown around.

 

[soutthpaw]

I mentioned before that studies show that 900-1200pls are preferred by most users. I had 2400pls for a long time. Instead huge improvement when I went to 1200 and after using 900 and 1200 for a few months discovered my speech scores were best @900. So you can have too much of a good thing... Heh

 

[Foxrac]

Based on my experience, if you hate hearing aids so I don't recommended you to get CI.

If you like hearing aids but don't give enough sounds so CI is best option.

 

[mijo]

I mentioned before that studies show that 900-1200pls are preferred by most users. I had 2400pls for a long time. Instead huge improvement when I went to 1200 and after using 900 and 1200 for a few months discovered my speech scores were best @900. So you can have too much of a good thing... Heh

Thanks for continuing to comment. This is helping me.
Out of curiosity, did you do any music discrimination comparison with different rates? I know speech is the real goal, but it would be interesting to understand whether that has any effect.
Also, I expect a reduction in pls helped with battery life?
Have you also noticed whether AB users also choose lower rates like this?

 

[soutthpaw]

Thanks for continuing to comment. This is helping me.
Out of curiosity, did you do any music discrimination comparison with different rates? I know speech is the real goal, but it would be interesting to understand whether that has any effect.
Also, I expect a reduction in pls helped with battery life?
Have you also noticed whether AB users also choose lower rates like this?

I'm not in the CI banner waving club. So I'm not up on this constant one upsmanship between companies. Only sharing what I know about my own experiences. ( 11 years with bilateral CI, progressive Deaf. 235 mappings and several years in research studies) I could care less what device you choose and only wish you the best possible outcome with it. As for music I can now follow the rythum but singing in music sounds distorted and hard to follow. I would try asking very specific music questions on each of the individual manufacturer forums. But don't let on you are trying to choose a brand else most will give you sales pitch instead of honest answers. Say you or a family member or something is getting that brand and wants to know people's experiences with music and be specific to what type etc. Personally I think music sounds the most beautiful in ASL.
Do order that book I recommended.

 

[ecp]

Based on my experience, if you hate hearing aids so I don't recommended you to get CI.

If you like hearing aids but don't give enough sounds so CI is best option.

I hated hearing aids because I was too deaf to benefit from them so all I heard was noise.
With a cochlear implant, I hear clear sound at a comfortable level and don't spend hours everyday laying in bed trying to get my ears to stop ringing.

I even tried out a hearing aid in my unimplanted ear recently (admittedly it needs to be reprogrammed) but it was so loud and annoying that all I could hear was the fan when my CI ear was able to hear conversation without trouble.