Age-related (sometimes known as progressive) hearing loss is extremely common. But we know very little about its causes, and the processes which underlie it.
Studies have identified genes that are associated with a person’s hearing ability. We don't know exactly how they influence hearing, but it's likely that they play a role in age-related or noise-induced hearing loss.
We share 95% of our genes with mice, and our similar genetics, anatomy and physiology mean that we can study mice and extrapolate the research findings from using them to people. In particular, mice are useful in helping us to uncover what particular genes do throughout the body, including in the ear and in hearing, both under normal conditions, and when something goes wrong, for example in disease. Professor Steel and her team are working with mice in which genes known to be associated with hearing in people have been inactivated.
The King's College researchers are using these mice to investigate how six genes affect how we hear – and how they might cause age-related or noise-induced hearing loss.
They are testing the hearing ability of the mice and how susceptible they are to noise-induced hearing damage. They'll then examine any mice with abnormal hearing further to identify the exact cause of, and the biological processes underlying, their hearing loss.
This will include investigating the inner ear and the neurons that connect the sensory cells in the inner ear to the hearing brain. Even if their hearing is found to be broadly normal, other tests may uncover differences in their ability to distinguish different tones or timing of sounds – features which can cause difficulties in understanding speech in human hearing loss.
'This project will further our understanding of how genes influence hearing ability, and hopefully identify new targets for drugs to protect or restore hearing.'
By the time their research ends at the beginning of 2018, Professor Steel, Dr Ingham and Dr Buniello will be able to fill a big gap in our knowledge around the genetic basis of, and processes involved in, the normal variation of hearing ability – including variation in time of onset and severity of age-related hearing loss in people. Ultimately, this knowledge will help identify targets for drug development to slow down or stop age-related hearing loss.