Cochlear Implant Plus Hearing Aid - Bimodal Fitting

The NHS allows one cochlear implant per person, and the criteria say you must have a profound loss on both sides to qualify for that one implant.

So, we have an implant on one side that theoretically improves hearing massively on that side. We also have a contralateral (other side) ear that’s profoundly deaf - or at least in the frequencies that really matter.

Bimodal (two ways) fitting is where you have two different modes of hearing on one person. Implant on one ear, hearing aid on the other ear.

The NHS is not great at doing aids that help us to hear well in noise. It’s getting better, don’t get me wrong, but it’s not great. For decades now, the best way to hear in noise has been a pair of aids with adaptive, directional microphones, which “talk to” each other. These high tech aids swap information* between themselves and ‘focus’ front, sideways and backwards in tandem with each other. The best aids on the market can significantly improve speech reception in noise versus NHS tech.

When a customer wears a pair of private aids, they often have frequency compression in use, and they have this information-sharing going on too. If they get an implant then, they improve one ear dramatically with the implant but can no longer use their fantastic private aid on the contralateral side. It’s not compatible with the implant, and it no longer has its partner to work with. They also often lose the frequency compression settings that have been helping them, as the NHS audiologist is not aware of how the previous audiologist set them up.

Last year I sent a patient for implantation, expecting I would still see her for the contralateral aid servicing. I found that the NHS had fitted her with a crusty, giant aid on the contralateral side. She could hear very little out of it, and had been told it was “just for sound awareness” reasons. Basically, she’s doing all her hearing with the implant now, on one side.

Comparison of a private vs a Calderdale NHS aid for the same patient (severe-to-profound loss). They get even bigger than this too!

I do understand that the implant will be doing the heavy lifting, but it annoyed me that I’d spent years rehabilitating that ear, only to have it put out to pasture with a rubbish aid on it! “Only for sound awareness” indeed!

I wondered if there was a really good reason why the NHS does this. So I hit the research, and found (someone correct me if I’m wrong, please):

A) No, there’s no good reason not to do a bilateral (both ears) implant. One cochlear implant vs two is because they’re expensive, not because two would cause problems.

B) The reason the contralateral aid doesn’t work well is because it’s made by someone different to the implant manufacturer. The implant manufacturer doesn’t make an aid that communicates seamlessly with the implant. Therefore it becomes just for sound awareness, with no great expectations for performance. This is upsetting.

So. We are stuck with this system. But, we can do a “bimodal fit”, with a private aid, it turns out! As long as we choose the correct manufacturer and the correct model, which corresponds with the implant, we can have:

1) A better quality, private hearing aid on the ear that’s contralateral to the implant.

2) Frequency compression, if it was used in the old private fitting. The implanted side will hear high frequencies “naturally” via the electrodes. 3) We can have a receiver and custom ear tip instead of the travesty of an NHS earmould, standard tubing and nasty tubular distortion.

4) We can set the aid to stream audio at the same time as it is streamed to the implant (stereo streaming is so useful for phone calls and listening to lectures, videos etc).

As long as the audiologist is patient - and critically, does not interfere with the rehab process of the implant - they can then use their time to tweak and optimise a bimodal aid on the patient’s non-implanted side. Instead of just being for sound awareness, it can be actively supporting the implanted side!

Now I know I can do that, I’m deeply interested in becoming great at it! I’m partway through my training on this, and shortly I will be receiving a demo pair of GN Resound Nexia™️ aids.

Nexia aid family, courtesy of GN Resound

These are the approved aids that work well with the Cochlear™️ brand implants used in my local region, and I’ll be trialing these myself for a couple of weeks before I fit my first bimodal patient, Dinah**, once she has rehabilitated to her cochlear implant.

If you are an implant patient, and want to know whether your hearing can be improved with a bimodal aid (or a higher quality bimodal aid), I recommend contacting your local independent audiologist. High street chain auds tend not to stock the compatible brands, and don’t have the time/energy to devote to the process.

*One of the ways this can help... If there’s a lot of noise on one side, the contralateral aid will send its cleaner signal across to the noisy side, so you hear two clean signals in each ear.

** Check out #dinahsjourney to read a real-time blog of my Mum (Dinah’s) implant progress.

***Huge thanks to GN Resound, who have donated Nexia aids to Dinah so that I can learn how to fit bimodal on a real patient.