DEAFNESS AND HEARING DEFECTS

Key facts

• 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, ageing and the use of 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.