In this project, Professor Rachael Richardson at the Bionics Institute, Australia, explores whether light stimulation can improve the quality and accuracy of sound transmitted to the hearing nerve for cochlear implant users through cochlear implants.
Project start date: May 2025
Project end date: March 2028
About the project
Cochlear implants provide a sensation of hearing to those who have severe to profound hearing loss. They use electrical signals to directly stimulate the hearing nerve.
To avoid overlapping electrical currents that could otherwise ‘blur’ the signal sent to the brain, the electrodes of cochlear implants are stimulated one at a time. However, this means the implant cannot send information about fine changes in the timing of sound information. These are critical for understanding speech in background noise, locating where a sound is coming from, and the perception of pitch and timbre of musical sounds.
Researchers have recently shown that light can be used to stimulate the hearing nerve more precisely than an electrical signal. This would require the cells in the ear to be modified using gene therapy to become responsive to light. In this project, the researchers will investigate whether light stimulation can improve the quality and accuracy of sound transmitted to the hearing nerve.
How it works
The research team will study deaf mice whose inner ear nerve cells have been genetically modified to respond to light. These mice will be given a cochlear implant that delivers either an electrical or light signal to the hearing nerve.
They will then compare light to electrical stimulation to see if it improves the quality of hearing through the implant.
How will this research benefit people with cochlear implants?
The results from this study will show whether light stimulation can provide a better sensation of hearing through a cochlear implant than electrical stimulation. This could ultimately lead to the development of improved cochlear implant technology that brings a richer listening experience to cochlear implant users.
About the researcher
Professor Rachael Richardson is Head of Optogenetics Research Program at the Bionics Institute, Australia.
Hearing, music and communication are such essential and enriching components of everyday life, and compromised hearing leads to anxiety and missed opportunities.
I am committed to doing research that improves outcomes with cochlear implants by using technologies to control nerve activity with high precision.”
