This is a Fellowship Grant awarded to Dr Przemyslaw Jarzebowski at University College London. It started in March 2025 and is funded by the Vivensa Foundation.
Background
Age-related hearing loss makes comprehension of speech in noisy backgrounds more difficult. When background noise is loud, successful hearing relies as much on the actual sounds as the predictions of what we will hear. This fellowship will address how such predictions emerge and can improve the detection of sounds in the brain.
Our brains seamlessly integrate the predictions from lip movement and previous words in the sentence. However, we still need to learn about how and where in the brain this happens. Similarly, we need to find out how these predictions are affected in people with age-related hearing loss, and whether future interventions addressing hearing difficulties can take advantage of these predictive signals created by the brain.
Research methods
The researchers will study auditory signals in the brains of adult and ageing mice. Mice are often used to model auditory processing in the human brain. As they age, their degraded hearing resembles that seen in people. The researchers will measure the electrical activity of individual cells in the mouse brain and its auditory cortex – the brain area central to hearing – while the mice listen to repeating sound pips. The predictability of the repeated sound leads listeners to develop an expectation about the sounds to come. By recording brain activity when the expected sounds are omitted, the researchers can gauge the strength of these auditory predictions.
Because background noise masks the sounds we intend to hear, hearing in such environments may require more reliance on predictions. To answer this, the researchers will compare the brain’s activity in the presence and absence of background noise and test how it differs in age-related hearing loss. These comparisons will tell us whether stronger auditory predictions that compensate for the noise could also be how the brain compensates for the degrades sound information it receives in age-related hearing loss. Lastly, using genetic tools to control the activity of selected brain cells, the researchers will test the role of a part of the brain called the hippocampus in supporting this predictive hearing.
Benefit
This study will help uncover how and where in the brain our predictions about upcoming sounds are integrated with actual sound information to support hearing. As a result, we will better understand the interaction between the brain signals generated by sounds and those generated internally by predictions, and how their respective role and interactions change in people with age-related hearing loss.
This knowledge could be used to design new interventions that improve hearing by selectively targeting and enhancing the brain’s predictions about sounds.