WHO: One billion youth at risk of hearing loss from loud audio In a bid to address the hearing health concerns of headphone users, Shelly Chadla, director of the hearing loss prevention department at WHO, discusses the WHO decision to issue non-binding regulations on the volume of audio devices. About 50% of young people aged 12 to 35, or 1.1 billion people, are at risk of hearing loss due to "prolonged and excessive exposure to loud sounds", according to the WHO. IMAGES of the press conference and SOUNDBITES from Shelly Chadla, director of the hearing loss prevention department at WHO