Anatomy Based Fitting works best with deep electrode insertions

[Mary Beth]

@Lauren

Will you type what the key in the top left corner says?

[Lauren]

@Mary Beth sure. 

Grey highlight: Calculated frequency bands

Red Highlight with white dot: Current frequency band

Black dot (no highlight): Anatomy-based OC center frequency

White Hz inside black highlight: Frequency range 

[Mary Beth]

@Lauren

if the issue you had uploading was that it said your allotted space was full, send a HP message to the moderator and request more photo space

[Anthony Canada]

@Laurenthank you for sharing that graph. It is one of the graphs I've been wanting to see for my own hearing and now I know what it looks like! I also have the 28mm insertion and on mine half of electrode 11 and all of electrode 12 are not useful. The issue is on my end not the electrodes. If you like I can share my graph when I get it so that we can compare. 

[MED-EL Moderator]

Hi @Mary Beth,

thank you for your question. We consulted our experts, and they sent us the following studies:

• Using Anatomy-Based Fitting to Reduce Frequency-to-Place Mismatch in Experienced Bilateral Cochlear Implant Users: A Promising Concept - PubMed (nih.gov).  The most recent paper, it has 10 bilateral CI users as subjects.
• One Click Is Not Enough: Anatomy-Based Fitting in Experienced Cochlear Implant Users - PubMed (nih.gov).

Kind Regards,

Giulia

[Mary Beth]

Thank you @MED-EL Moderator Giulia

[Mary Beth]

The most effective angular insertion depth for ABF remains interesting to me as many of us do not have that angular insertion depth.  But it makes sense that electrodes would need to be deeply inserted so we can avoid a frequency upshift.

@Lauren @Tim

This is was quoted from the above links

”Additionally, two approaches of reducing the frequency-to-place mismatch revealed that participants are more likely to accept the ABF map if their electrode array is inserted deep enough to stimulate the apical region of their cochlea. This suggests an Angular Insertion Depth of the most apical contact of around 720°-620°”

 

”however, acceptance was only established if the point of first electrode contact was less than 230 Hz.

Conclusions: ABF mapping increased the acceptance in CI users with longer electrode arrays and in bilateral CI users who were unsatisfied with their device experience”

[Tim]

Great.  Thanks for the meaty reads Moderator and @Mary Beth.  I'm going to have to dive into these papers. 

I fit their criteria for a good candidate for ABF but if had done a detailed testing in the clinic and was less willing to accept a "one step back to take two steps forward" - I probably would not have "accepted the ABF map" myself. 

I took a quick read through the first paper.

• Using Anatomy-Based Fitting to Reduce Frequency-to-Place Mismatch in Experienced Bilateral Cochlear Implant Users: A Promising Concept - PubMed (nih.gov).  The most recent paper, it has 10 bilateral CI users as subjects.

Quote

"Our results show that, with the ABF mapping, speech understanding in quiet increased slightly (but not significantly) in the reference ear-only setting and significantly in the bilateral set up. Further, average speech understanding in quiet in the contralateral ear-only mode slightly decreased with ABF, although not significantly. "

If I'm understanding it right, using ABF helps the two CIs better match frequencies which helps in bilateral applications even though the individual ear performance one at a time (isolated) is not showing much or significant improvement at that time. I had not thought about bilateral but that seems reasonable.   It seems like the tests were all done in same appointment with no re-adaptation time.  If so, I'm really surprised that they report that users were pleased with the ABF sound quality.  Even a week in, I would still say speech understanding on my CI alone (ex. streaming) was poor compared to my previous MAP.   It would seem like the experience would improve over time but the authors seem to be careful to not speculate on that.

Their ten patients all seemed to have the second CI for at least half a year, similar to me so I'm surprised re-adaptation is not discussed more in the paper.

The paper is pretty dense and not in my research area so I'll need to read more carefully later. Please let me know if others have different interpretations.

My audiobooks from Libby are coming off hold and it is really hard to do them after feeling like I could plow through them pretty easily pre-ABF.  Like @Lauren said, I think things will get unscrambled in a few more weeks.  My #1 piece of advice for people with newly implanted long electrodes (28 mm+) is to push for a post-op CT and possible ABF as early as possible.  The longer you wait, the harder/longer a possible ABF adjustment will likely be.

 

[Lauren]

I actually just heard back from Sarah and she was able to provide some of the information I was looking for. Waiting on clarification of a few points to make sure I’m reading the report correctly. 

[Mary Beth]

@Tim

Sometimes changes bring us to a better place and other times they don’t.  When I participated in Vanderbilt’s image guided CI programming study, they told me it would take time to adjust.  They tested me prior to their changes and then I returned one month later for a comparison test after I had adapted to the changes.  I was then free to choose to return to my previous MAP or stay using their image guided parameters.

And it did take adjustment and my brain was tired for a bit.

But there was also an immediate benefit, which motivated me to make the adjustments.

This was in late 2016 and I am still choosing to use their parameters for my MAPs.

If I had not found Vanderbilt’s image guided programming beneficial, I would’ve switched back to my previous MAPs.

In time you will know if this ABF is a good fit for you.  Trust your instincts.

[Lauren]

Wow - I was reading it correctly and not sure what to make of it but there’s a 30% difference in insertion depth. I was not expecting that much of a difference between sides. 

[Mary Beth]

@Lauren

same electrode array in each side?

I wonder what is an average difference between AID ?

Maybe 30 degrees is very common.

 

 

[Lauren]

@Mary Beth yes same Flex 28

The % I’m referring to is the difference in estimated cochlear duct length occupied by the electrode arrays. One side has almost 30% less cochlea coverage than the other and I wasn’t expecting the angular insertion depth to have as high a number as I am seeing. When I saw the report I was instantly shocked. 

[Mary Beth]

@Lauren

How does that info match with your experiences with each side?

[Lauren]

@Mary Beth 

I’m not sure anymore. At least in my case a deeper insertion doesn’t mean the ear is easier. If you’d like me to be more specific we can private message. 

[Lauren]

Still mulling over the results of my appointment but did get booth tested. 

Single words: was tricky because they were done at a quieter level however my audiologist wanted to make it hard and making it louder would’ve defeated the purpose of the test. I lost a little ground with my right ear however the left increased by 20% and the slight drop on the right actually made the two ears pretty much equal. Ears were also tested together and it was a typical result for me. Single words are always harder for me. Audiologist said she’s seen it happen with bilateral before so I’m par for the course. 

Sentences: I always get around 90% or so and today I didn’t get to know my exact score and that’s ok. All I know it was better than ever so maybe just a slight increase there. 

Next appointment will be in November around my one year mark and hoping to see results then. At least for this test my brain did me the courtesy of unscrambling a few weeks ago.  
 

Other items: got my right Rondo fixed, slight increase in volume on just that one processor, and then got all processors loaded with the third program. Got the processor data refreshed in the AudioKey2 app before leaving as well. 

[Tim]

I had the ABF done 4 weeks ago and as I said, I'm giving an update on progress.  I was not surprised that after ABF, it felt like I had gone back pretty far in my rehab.  Perhaps to the equivalent of being at the 1 or 2 month level of performance. 

I've been doing an hour or two of streaming every day to try to adapt to the new frequencies.  I'm seeing small progress on voices but directly streamed audiobooks and podcasts are still much harder than they were before ABF. 

As another test, this morning I tried talking with the person that I did phone calls with at about the 3 month post-activation mark and I couldn't make it out as well as I did then. 

I've been only using the ABF map for 4 weeks but I'll be curious to see what my Audi has to say and suggests for a followup plan.  I have another 1.5 weeks before my ABF followup appointment and keeping fingers crossed it improves.  

 

[Tim]

I said that I would continue to post updates on my ABF experience. 

I just had my first followup after ABF.   It had been about 6 weeks of using nothing but the ABF reassignment of electrode frequencies.  I was working hard on rehab exercises to give it the best shot possible at improvement.  (Averaging at least 2 hours a day of direct BT streaming to my CI.)

Qualitatively it felt like I still was underperforming pre-ABF.  Turned out I was right. 

Word recognition scores:

• 11% - before CI
• 44% - at about 3 months post-activation
• 64% - at 6 months (pre-ABF)
• 24% - after 6 weeks of using ABF.

I still feel like I'm picking up a little more clarity or resolution in some high frequencies but voices are too muddied.

My Audi offered to go back to the original or try adjustments and a quicker next appointment in early October.  I opted for the latter but barring a dramatic change, I expect that I'll probably toss in the towel ABF at that point and go back to the original default frequency allocation.

I don't want to dissuade people from trying ABF.  It may be more helpful in other cases, particularly:

• if done earlier in the rehab process,
• as Mary Beth mentions in the subject line, with longer electrodes and deeper insertions, particularly with the new 34 mm electrode to pick up the lower frequencies better (I had a 31 mm so I had a fighting chance for success),
• where electrodes 11 and 12 are inserted deeply enough to map better to the maximum frequency of the processor (Med-El CI's go up to 8500 Hz but my electrodes 11 and 12 would be ABF mapped to higher than that), and 
• with retained residual hearing.

Still glad that I gave it a try. 

 

[Lauren]

@Tim sorry it hasn’t worked out for you, but kudos for trying and sticking with it!

[Mary Beth]

@Tim

It’s great that you are so perceptive of how you are hearing with your CI and that the testing confirms it.  Anatomy based fitting is an option but it is not a great fit for everyone as you mentioned.

There is nothing to lose by trying new approaches and nothing to lose by returning to previous approaches that are a better personal fit.

You will still have those post op images to use if you ever wish to test out a future version of ABF.

 

We will miss you on Sunday and look forward to next time.

[Tim]

@Mary Beth Thanks.  I think this will be my first Sunday morning Google Meet I've missed in almost a year!  Alas, my daughter's last college Parent's weekend beckons! 

I'm glad that I won't be left wondering whether I should have tried ABF or whether I gave it a sufficient test.  Happy that it has worked well for other people (including @Lauren) - everyone's hearing journey is unique.  Hopefully our experiences will be of some small help for someone in the future.

 

[Jullannie]

Attached is a link to a current trial on Place Based Mapping (PBM) which is similar to Anatomy Based Mapping. It’s currently being conducted at several clinics including UNC-Chapel Hill.  One of the differences between the two mappings is that electrodes are not turned off in the high frequencies. It also uses a customized and different program than the MedEl version. The trial is using only MedEl and it blinds the volunteers with traditional and place based mapping. 
https://clinicaltrials.gov/ct2/show/NCT05558514

[John F]

Is there any study or experience about ABF and music?  I’d think with the changes to the frequencies of the electrodes and such it is beneficial for that but unless I’ve skipped something, I’ve not actually seen much mentioned.

[Lauren]

@John F I actually had a good experience with ABF and music. I tried right away and familiar songs sounded good. I still struggle with new/unfamiliar songs and those that are too “busy” with instruments. That will just take more time to get used to. 

Also, as Tim shared, ABF wasn’t right for him so experiences will be different for everyone. 

[Jullannie]

The above trial will look at music quality and pitch as well as spatial and localization parameters. They will also try to see if there is hearing in noise improvement. Lots of the excitement comes from studying EAS and SSD patients. This trial is focusing on long arrays but future applications for shorter arrays and different CI brands are in the works.