Hearing partially improved when nerves in the ear, which pass sounds into the brain, were rebuilt in gerbils – a UK study in the journal Nature reports.
Getting the same improvement in people would be a shift from being unable to hear traffic to hearing a conversation.
However, treating humans is still a distant prospect.
If you want to listen to the radio or have a chat with a friend your ear has to convert sound waves in the air into electrical signals which the brain will understand.
This happens deep inside the inner ear where vibrations move tiny hairs and this movement creates an electrical signal.