At the moment, cochlear implants (CIs) convey speech and sound by electrically stimulating auditory neurons. The cochlear implant has up to 22 electrodes that are positioned in the cochlea. These separate out sounds according to their pitch.
In the cochlea there are usually thousands of sensory hair cells doing this job, each one responding to a slightly different pitch. So, for someone using a cochlear implant, it’s harder to separate out different sounds – making it difficult to follow conversation when there is background noise, or to listen
We’re hoping that, by using electrodes that fire tiny beams of focused light at the auditory nerve, rather than electric currents, we’ll be able to stimulate the auditory neurons more precisely. Cochlear implants can deliver pitch information to the cochlea because the nerves in our ears are arranged much like piano keys. Those at one end of the cochlea (or keyboard) receive low-pitch sounds and those at the other end, high-pitch sounds. But the electric current emitted from implant electrodes to activate the nerves, or press the keys of the piano, ripple out just like dropping a stone in some water. This ‘spread’ of activation means that a single electrode may activate a mix of low and high-pitch nerves at the same time. Imagine what listening to music would sound like when this happens!
If we can overcome this spread of activation in the cochlea, we can come closer to conveying not just pitch information but the full richness of complex sound – such as a piano.
I love the way cochlear implants have helped people with hearing loss to communicate, interact, work and learn. It would be exciting if we could go further to enable hearing in the presence of competing background noise, appreciation of music and other complex sounds.
I enjoy the applied science nature of my current research – I enjoy having a problem to solve, I like that the outcomes are tangible, I love that there is a real chance of a discovery that is game-changing for science and for people with a cochlear implant.
Action on Hearing Loss has been enormously supportive over the past 10 years. One thing that really makes your UK-based charity stand out is that you fund cutting-edge research projects, no matter where they’re based in the world. Action on Hearing Loss also funded my research into gene therapy for protecting and regenerating the sensory cells in the cochlea. The overall aim is to be able to reverse hearing loss – how amazing would that be!
One thing that really stands out for me is the potential for gene-editing technologies to treat certain forms of genetic hearing loss. Scientists are already seeing prevention, or reversal, following gene therapies in animal models. I believe that we’ll be seeing similar, promising results in clinical trials in the near future, whether from gene therapies, stem cell therapies or from pharmaceutical treatments.
I started my career doing molecular-based cancer research. While this was fascinating and rewarding, I’d say to anyone thinking of working in the hearing research field that I’ve not regretted my move. I’ve found people working in this area to be collaborative and, with organisations like Action on Hearing Loss around, there is important support for researchers.
Any kind of research requires a cohesive team who all have a role in advancing knowledge that can be developed into treatments for people to live better. I’m lucky to be working with internationally renowned scientists in neurophysiology, neuroscience, physiology and optical science.
My ultimate goal is to be an integral part of that team that gives better hearing to people through advances in cochlear implant technology – and therapies for the protection and regeneration of the ear’s sensory cells.
Find out more about cochlear implants at: www.actiononhearingloss.org.uk/how-we-help/information-and-resources/publications/hearing-aids-and-cochlear-implants/cochlear-implants/
The Bionics Institute, Australia
In medicine, ‘bionics’ means the replacement or enhancement of organs, or other body parts, by mechanical versions. Bionic implants mimic the original function very closely – or even surpass it.
Rachael Richardson says, “At the Bionics Institute, we’re passionate about multidisciplinary research and product development that leads to clinical outcomes that improve lives.
“We’re focusing on improving outcomes for people with hearing loss and we’re exploring a range of new devices for the alleviation of symptoms associated with neurological disorders and inflammatory conditions.”
Go to: www.bionicsinstitute.org
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