Scientists may have found a gene which causes the most common form of deafness and hearing loss in adults.
The condition, known as otosclerosis, affects one in 250 people and is caused by genetic and environmental factors.
It is characterised by abnormal growth of the bones in the ear.
The study linked the TGBF 1 gene to the development of the condition which can cause total deafness.
It is thought that the discovery will enable scientists to look at methods of "switching off" the actions of the gene to prevent the onset of otosclerosis.
Melissa Thys, who led the research team, said: "We were able to conclude that we were the first to identify a gene that influences the susceptibility for otosclerosis. And as further evidence, we were also able to show that a more active variant of this gene is proactive against the disease.
She continued: "This may lead to a better form of treatment in the future; currently the best option is an operation."