This is a Discovery Research Grant awarded to Dr Tobias Goehring at the University of Cambridge in 2023.
Many people with severe or profound deafness do not benefit from using hearing aids, which make sounds louder but not loud enough to help them hear well. They may therefore choose to have a cochlear implant, where small electrodes are placed in their inner ear by a surgeon to send sound directly to the hearing nerve via electrical signals.
Cochlear implants also have an external microphone that picks up sound information from the outside world and transforms it so that the electrodes in the inner ear can use it to send signals to the brain. The changes that are made to the sound by the cochlear implant are called the ‘Sound Processing Strategy’.
Cochlear implants are used by around 1 million adults and children worldwide. For most people, they work well for understanding speech in quiet places. However, one of the most common difficulties for people with cochlear implants is that they find understanding speech in noisy places, such as a restaurant or classroom, can be very difficult and make communication in everyday life challenging. These difficulties often lead to people withdrawing from social situations, which can have a negative impact on their mental health.
In this project, Dr Goehring and his team aim to reduce the communication difficulties that people experience with cochlear implants. Their goal is to improve the Sound Processing Strategy used in cochlear implants to improve speech understanding in noisy situations. They will achieve this by simplifying the pattern of electrical signals sent to the hearing nerve.
They have produced a computer programme that analyses the sound information after it has been transformed by the cochlear implant and removes parts of the electrical signals that are not heard by the listener. Their early results have shown that this approach can improve speech perception in noisy places for people listening with cochlear implants.
The research team wants to better understand what causes these improvements in speech perception and to use these findings to improve their approach to achieve even greater benefit in speech understanding for people with cochlear implants. Removing parts of the electrical signals that are not needed for hearing will also reduce the electrical power required by the cochlear implant. They will measure the electrical power savings and associated increase in battery life with their Sound Processing Strategy.
If successful, this research will lead to improvements in speech understanding for people using cochlear implants. The Sound Processing Strategy could be used by all cochlear implant companies to make their products work better, making the benefits of the strategy widely available. This will enable people who are currently using cochlear implants to access the benefits of this strategy without needing further surgery.
Most importantly, the Sound Processing Strategy could help to reduce the communication difficulties that people with cochlear implants face in their daily lives. By saving electrical power, it could make cochlear implants more energy efficient which could ultimately lead to smaller, more convenient cochlear implant devices.