The UN agency estimates that 360 million people suffer from hearing loss worldwide, and apart from noise related causes and aging, it is also brought on by infectious diseases, genetic conditions, complications at birth, and use of certain drugs. The WHO considers a volume above 85 decibels for eight hours or 100 decibels for 15 minutes as unsafe. It estimates that around half of those between the ages of 12 to 35 in middle- and high-income countries are at risk due to unsafe levels of sound on personal audio devices or smartphones, while another 40 percent are at risk from damaging audio levels at concert venues and night clubs.
Shelley Chadha, a WHO specialist on hearing impairment, said, "More and more young people are exposed to unsafe levels of sounds. Young people should be aware that once you lose your hearing, it won't come back."