Key findings (WHO. 2006)

• In 2005, about 278 million people had moderate to profound hearing impairment. 80% of them live in low-and middle-income countries.
• Infectious diseases such as meningitis, measles, mumps and chronic ear infections can lead to hearing impairment. Other common causes include exposure to excessive noise, head and ear injury, aging and ototoxic drugs.
• Half of all cases of deafness and hearing impairment are avoidable through prevention, early diagnoses and management.
• Current production of hearing aids meets less than 10% of global need. In developing countries, fewer than 1 out of 40 people who need a hearing aid have one.
• An estimated 700 million persons could be affected with hearing loss by 2015.
• The number of people worldwide with all levels of hearing impairment is rising mainly due to a growing global population and longer life expectancies.
• Chronic middle ear infection is the main cause of mild to moderate hearing impairment in children.
• The impact of hearing impairment on a child’s speech, language, education and social integration depends on the level and type of hearing impairment, and the age of onset, especially if it begins before the age when speech normally develops.
• 50% of deafness and hearing impairment is avoidable through prevention, early diagnosis, and management.