There are thought to be only 60 cases of Foreign Accent Syndrome in the world. People who have it start speaking with an entirely different accent.
Kay Russell, from Bishops Cleeve near Cheltenham, suffers from the extremely rare neurological disorder. After a serious migraine, she woke up with what sounds like a French accent.
Doctors believe it is triggered following a stroke or head injury, when tiny areas of the brain linked with language, pitch and speech patterns are damaged.
Read more and watch a film on the BBC website.