Hearing loss basics

If you have hearing loss, you are definitely not alone. Hearing loss affects hundreds of millions of people around the world. Across this huge cross-section, hearing loss affects people for many different reasons and in a variety of ways.

Hearing loss may come on gradually, as typically happens with noise induced hearing loss and hearing loss that comes with age. Or it can be happen suddenly. It may affect one ear or two. It could stem from a problem in the inner, middle or outer ear, or from problems in a combination of places. Hearing impairment may reduce the ability to hear high-pitched sounds or it could impact low-frequency hearing. Hearing loss can be mild, moderate, severe or profound, and its severity may change over time.

How hearing works

Want to know how hearing works? Learn more about the miraculous process of how we hear.

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Hearing loss causes

The causes of hearing loss and deafness can be divided into congenital causes and acquired causes.

Causes of hearing loss

Types of hearing loss

Learn more about the different types of hearing loss, including conductive hearing loss, sensorineural hearing loss and mixed hearing loss.

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Degrees of hearing loss

Degrees of hearing loss, mild, moderate, severe, profound

Learn more about degrees of hearing loss


The information on this website is for educational purposes, and is not intended to replace medical advice. Please consult a hearing healthcare professional to diagnose or treat a hearing or health problem.

Hearing checklist for children

See some hearing milestones your child should reach in the first year of life, and learn about the signs of hearing loss as your baby grows into a toddler.

Learn about the signs of a hearing loss