SCIENTISTS at the University of Brighton have moved a step closer to understanding the cause of age-related hearing loss which affects 11 million people in the UK.

Hearing loss is believed to originate in non-sensory cells in the cochlea, the auditory portion of the inner ear.

The cells are coupled together by ‘gap junctions’ formed of two proteins called connexin 26 and connexin 30.

Mutations or failures in these proteins cause most cases of hearing loss.

However experiments by the university’s sensory neuroscience research group have shown that one particular mutation in the connexin 30 protein actually prevents deafness to high- frequency sound.

Professor Ian Russell, the university’s Professor of Neurobiology and a member of the group, said: “This was a great surprise.

“The mutation should have impaired the function of the cochlea, not aided it.

“Other members of the research team are now making direct measurements from these supporting cells to understand how the mutation changes the properties of the gap junctions.

“They should obtain measurements that will enable us to understand how the mutation alters the electrical and mechanical properties of the cochlea and eventually lead to our understanding how sensitivity is preserved in a cochlea that would otherwise be decimated by age-related hearing loss.”

Professor Russell explained how the research has led to new insight into how we hear.

He said: “The convention is that sound energy is converted into electrical energy in the cochlea through modulation by sound of a flow of current through the sensory cells which is provided by a battery in the cochlea.

“We discovered that the voltage of the cochlear battery is almost halved in the mutants, but voltages across the entire sensory cells of the cochlea remain unchanged. “