WHO believe 1.1 billion people are at risk of suffering permanent ear problems through their listening habits - and that over 43 million people between the age of 12 and 35 are already living with hearing loss.

The health body says in a report: "The emerging pattern of listening regularly at high volume and for a long duration poses a serious threat. While it is important to keep the volume down, limiting the use of personal audio devices to less than one hour a day would do much to reduce noise exposure."