Cochlear Clinical Night

I have just come back from a Cochlear Clinical Night hosted in Singapore – the speaker was Brendan Murray, a cochlear implant specialist from Sydney. Some of you might be aware that he’s Lina Lim’s predecessor (Lina Lim is the area manager for South-East Asia), and was the first one to help set up Cochlear’s operations here in Singapore.

The talk was primarily for medical professionals and clinicians – but I found out and requested admission which was granted readily (thank you, you know who you are!) There were two main parts of the talk – clinical outcomes for Freedom, and the future of their implantable devices. Please take note scores provided below might not be accurate – they are from memory.

Cochlear did a Freedom trial on 71 postlingually deafened adults in North America. I think you should be able to know that results were fantastic according to them. Let’s go straight to the more exciting part- the implantable devices.

There are now apparently 3 new or upcoming implantable devices by Cochlear other than Freedom on the market – the Hybrid S, Hybrid L, and Auditory Brainstem Implant (ABI). The Hybrid implant is an alternative option for those who are worried about losing their residual hearing - it combines the benefits of both acoustic and electrical processing – in other words, it tries to combine the functions of a hearing aid and a cochlear implant. 

The Hybrid S measures about 10mm, and is jointly developed by the University of Iowa and Cochlear. Research results on Hybrid S have shown that pitch perception scores of trial recipients can be quite close to that of normal hearing (90% in some cases, as compared to 60-70% for Long Electrode/the traditional CI).

The Hybrid L measures about 16mm, and word recognition scores have apparently created a new industry benchmark – word recognition scores hit above 50% for 3 months postoperative implantees from just around 2-6% preoperative.

The Auditory Brainstem Implant (ABI) section was very interesting. It’s an alternative for people with cochlear implant failures, or are found to be unsuitable for cochlear implants – NF2 (Neurofibromatosis Type 2), cochlear asplasia, cochlear nerve agenesis, ossified cochleas etc. It’s implanted directly at the cochlear nucleus at the right side of the brain at the bottom (if I’m not wrong), allowing direct stimulation. However, trials found that there was stimulation of other parts of the brain that was not auditory in nature, causing side effects – dizziness, aches and pain in other parts of the body ie. eyes, chest, legs.

Personally, I felt that Cochlear needs to integrate pitch perception tests as part of their testing. Not only that, I was wondering about how a bilateral and a Hybrid would compare against each other on word recognition scores (although I’m sure a Hybrid wins hands down on pitch perception). I also felt that the ABI was a kind of dead end – it had many reported side effects, and there was no complete open set recognition of words for the postlingually deafened individuals – which says a lot. Not many benefited, and those who benefited still had to use lip-reading cues to aid listening. Nevertheless, some form of listening is better than none at all – only without side effects, however!

Nevertheless, the Hybrid represents a new advancement in cochlear implants for individuals with severe hearing loss. It is much better than the long-electrode traditional cochlear implant, judging from independent research and anecdotal experiences. Individuals with such hearing loss, and are worried about their residual hearing not being utilised need not worry further with this new CI.

Hopefully, for the rest of us who are already implanted, a fully implantable device or cochlear regeneration is not too far off in the future.