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1 + 1 = 3

Posted Oct 12 2011 8:32pm
Imagine you were born with no legs. Years later, you are given an artificial leg. It works perfectly, but you have to learn how to walk with it. When you’ve never had a leg before, you’ll struggle to learn how to walk. You have  spent a year learning how to walk with the first leg. It’s not perfect – but with a crutch, it is so much better than having no legs at all. Then you’re given a second leg. The first leg helps the second leg to learn the movements necessary for walking, so the newer leg learns at a much faster rate and helps to improve the ability of the first. Each leg helps each other. The combined input of two legs is greater than one leg alone. Two legs are much easier to walk with, requiring less effort and being less tiring than managing on just one leg.

So it is with bilateral cochlear implants.

My ability to understand speech has changed significantly in the four weeks since activation of my sequential cochlear implant. It’s been a very different experience from my first cochlear implant, with a very different outcome.

Within two weeks, voices shifted to a lower tone and Donald Duck left the house very quickly. He took eight months to leave last year! I reached full volume after three weeks. My tinnitus has disappeared from my newly implanted ear, buzzing in my first implanted ear only when I’m tired. I can detect environmental sounds but not always recognise them …. yesterday, I got confused between a crow and a reversing truck! I’ve been so busy since activation that I have not done very much specific rehabilitation work.

+ Summative effect

The learning curve of the sequential cochlear implant has been much quicker than the first, as my brain already knows cochlear implant sound. The older cochlear implant is helping the newer implant as it learns, and the newer implant is helping the older implant by giving it a boost with more sound. The summative effect has reduced the effort it takes for me to listen, and makes speech comprehension easier.

+ Localisation of sounds

Two weeks after activation, I was in a lift (elevator) exiting the underground, and it was packed full of people. A man was talking to his son in a loud voice, and I was able to detect where he was – behind me and to my left. HA HA – brilliant! That was the first time in my life I was able to localise a sound. Since then, I have enjoyed being able to work out whether sounds are coming from my left, right, or are in front of me. If a sound is coming from the side, it sounds louder on that side. If it is in front of me, it sounds the same in both ears. Recently, I went to a cafe and sat there nursing a coffee, listening to the sounds around me and working out where they were coming from. I got annoyed when two women sat near me as they had such loud voices – all very definitely in my right ear! The chef was definitely chucking pans around in my left ear – peaceful it wasn’t!

+ Speech in noise

I have noticed an improved ability to hear speech in noise. However, I’m still lipreading full time! It’s now easier to concentrate on a speaker in a noisy environment but this is still pretty difficult.

+ Head shadow effect

With one cochlear implant, I was unable to hear sounds on my opposing side as my head acted as a barrier. It was weird to have excellent hearing on one side and nothing on the other.

+ Binaural hearing

Unilateral hearing was such hard work. I could understand the odd few words here and there, but never enough to pull a string of sentences together. I feel that the past year has been such a struggle. It was worth it, but it’s been a struggle nonetheless. My remaining ear was very poor and deteriorated further over the last year. I felt as if I was about to fall over into the abyss, I was walking on a knife edge with white light on one side and darkness on the other, my world was so unbalanced. Now, everything feels right again. I say ‘again’, because I always wore hearing aids in both ears, even though my left aided ear didn’t help me at all, it just gave me a little bit of balance to my world. Wearing a hearing aid on my second ear made me feel ill, as the sound signals were so different, and competed against each other for attention. Having two good ears feels natural and although one cochlear implant on its own sounds flat and odd, the two together give me sound that is somehow ‘whole’. I am already ‘centering’ sound, it doesn’t feel like I am wearing two separate hearing devices. It feels like I am wearing one device somewhere in my head. Two implants make the world seem whole and solid, I feel as if I am ‘centred’ within my sound environment, and everything sounds much more natural. One cochlear implant on its own sounds wrong and skewed, whereas two together sound balanced and … just right. Whooo. I am just LOVING stereo sound!

I wondered whether the outcome would have been different, had I chosen to implant my better ear first. My audiologist says it wouldn’t have mattered. Hearing is a brain thing. Once the brain knows cochlear implant sound, the second implant is clued in much more quickly.

+ FM system

I tried an FM system last week. I had used one at school until my hearing deteriorated too much to hear with it. I remember it giving me a clear voice, directly into my ears. If the teacher forgot to take off the transmitter microphone and wandered to the other side of the school, I would clearly hear every word until I found her! Every September, I would hear unintelligible mush until suddenly one day I would wake up, my brain had ‘sorted it all out’ and I would understand every word for the rest of the academic year. The long summer holidays were always my downfall, and in September I would have to learn to hear all over again. With excitement, I charged up each piece, connected the system, and prepared to listen. Complete stone-dead silence. I checked all the pieces were switched on and set correctly. Still nothing. I thought my cochlear implant batteries must have died, so I switched them for a fully charged pair. Still nothing. I checked all the settings again.  I plugged into my iPhone’s radio …. silence. I couldn’t understand it. I was getting really frustrated and starting to panic. Then I had a lightbulb moment. I switched the processors from one ear to the other, and hey presto! there was sound. I almost hit the ceiling with how loud it was, with the volume at the lowest setting possible.

Remember to wear the correct processor on each ear! I now colour code my (L)eft magnet with a b(L)ue cap.

+ Hearing test (October 2011)

A hearing test was carried out on my right cochlear implant only (red line), and then with both cochlear implants together (blue line). My audiogram proves that my hearing with two cochlear implants is better than with just one!


+ Speech comprehension scores

Speech was immediately easier to understand with two implants. On my way to my first mapping session after activation, two days after switch-on, I was listening to Stephen Fry talking on my iPod – using only the new ear.  I didn’t have time to look for the correlating printed book so thought ‘Ahhhh I’ll just do without’. I was able to understand bits of sentences …. amazing. Just amazing. In the speech discrimination tests, I scored 85% with single words and 100% on sentences. I got most word pairs and discriminations right (e.g. nip/lip : distinguish which one is being said).

We compared the second implant at one month old against the first implant at one month old. In the testing booth I scored 19% in word and sentence tests, which was much better than my first implant which scored pretty much zero! We then tested my speech perception in a more realistic setting as my speech therapist read a story to me, The Emperor’s New Clothes. Last year, with one implant, I scored 83%. This year, with two implants, I scored 93% – against the background noise of road works in the street outside.

I’ve been having conversations with people I know well – ENTIRE conversations. !!! No lipreading! Both on Skype and in real life. It’s not easy and I don’t get every single word, but it’s certainly much easier with two implants. *screams in delight*

+ Music

I was tested on Cochlear’s Sound and Way Beyond software and scored 97% in music and melody perception on my new ear alone. Already, music sounds quite good, and I have only listened to around six hours of music since activation. Advanced Bionics don’t offer a binaural direct connect lead so I bought a splitter from an electronics store to enable me to listen to my iPod with both ears. (More on this in another post.) Bilateral music is just …….. awesome.   *sobs*

The only hitch I’ve had is feeling as if sound was quieter and less complete with my new implant, in comparison to my older implant. We eventually realised the implants had different IDRs (Input Dynamic Range). The older implant is set at IDR 70 and the newer implant was set at IDR 60 – once the IDRs were set to the same level, the world sounded much better. I tried them both at IDR 60 for a few days, then both at IDR 70 for a few days, and couldn’t really tell the difference. Two implants are giving me so much more hearing that I am happy enough with a lower IDR – but I just decided to stick with IDR 70 for both. Both implants have IDR 80 for music. – I’m a sound junkie!

I’d recommend Arlene Romoff’s book, Listening Closely: A Journey to Bilateral Hearing . She offers a lot of great insights into what it’s like to have two cochlear implants. My cochlear implant team have seen very few bilateral adult recipients. The evidence of the benefits of going bilateral is thin on the ground in the UK, particularly for those who, like me, were born profoundly deaf.

Going bilateral has been absolutely incredible. It’s been better than I’ve dreamed and hoped. I didn’t even need all my mapping sessions as I progressed so fast. I’ve never been able to hear well with two ears nor benefited from bilateral hearing, but wearing two hearing aids all of my life, lots of rehabilitation work, Auditory Verbal Therapy sessions, and the cross-over training of the sequential implants have really set the scene for my success. If you’re thinking of going bilateral and you’re hesitating … don’t wait one second longer! Go for it and grab it with both hands! You’ll LOVE it!

*Crying buckets of happiness while doing the longest Snoopy dance with R*

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