Around 10 million people in the UK are deaf or have some degree of hearing loss, according to Action on Hearing Loss.
When hearing is lost, it may affect a person's quality of life and relationships.
Hearing loss may progress as a person gets older, or in young people, may result from long-term exposure to loud music, including from headphones.
Causes of hearing loss
Certain things, including age, illness and genetics, may contribute to hearing loss. Over several generations, modern life has added a host of ear-damaging elements to the list, including some medications and plenty of sources of loud, continuous noise.
Advanced age is the most common cause of hearing loss. About one in four people over the age of 50 have hearing loss; over 70% of people who are hearing impaired are over 70.
Researchers don't fully understand why hearing decreases with age. It could be that lifetime exposure to noise and other damaging factors slowly wear down the ears' delicate mechanics. Genes also play a role.
Noise wears down hearing if it's loud or continuous. In some workplaces, ears are exposed to dangerous noise levels every day. To understand the impact of noise, consider this: almost half of builders report some hearing loss. Other noisy lines of work include the military, mining, manufacturing, agriculture and transportation.
Even musicians, who literally create music for our ears, are at risk of noise-induced hearing loss. Some now wear special earplugs to protect their ears when they perform. The earplugs allow them to hear music without harming their ears' inner workings.
Certain medications can impair hearing and/or balance. More than 200 medications and chemicals have a track record of triggering hearing and/or balance side effects in addition to their disease-fighting capabilities. These include some antibiotics, aspirin, loop diuretics and medications for chemotherapy, malaria and erectile dysfunction.
Sudden hearing loss, the rapid loss of 30 decibels or more of hearing ability, can happen over several hours or days. (A normal conversation is 60 decibels.) In nine out of 10 cases, sudden hearing loss affects only one ear. The cause of sudden hearing loss can only be found in 10% to 15% of cases.
Certain illnesses, such as heart disease, high blood pressure and diabetes, put ears at risk by interfering with the ears' blood supply. Otosclerosis is a disease of the middle ear and Ménière's disease affects the inner ear. Both can cause hearing loss.
Trauma, especially that which involves a skull fracture or punctured eardrum, puts ears at serious risk.
Infection or earwaxcan block ear canals and reduce hearing.