Health A-Z

Medical Content Created by the Faculty of the
Harvard Medical School

Hearing Loss In Children

What Is It?

A child with hearing loss has trouble hearing sounds in the range of normal human speech. More than 7 million children have hearing loss, which can be present at birth (congenital) or can develop later in life (acquired). Hearing loss affects 17 in 1000 children under 18.It is one of the most common congenital problems in newborns, affecting one in 650 healthy babies. It happens even more frequently in babies born with other serious medical problems. Over 90% of deaf children are born to hearing parents, but the condition can be inherited — 5% to 10% of deaf children have deaf parents.

Unfortunately, hearing loss often is not detected until a child is 2, 3 or even 4 years old. Since the critical period for language development is from birth to age 3, the failure to identify hearing loss at a young age can have serious implications for a child's speech.

There are two major categories of hearing loss:

• Central hearing loss involves problems with the processing of information in the brain.

• Peripheral hearing loss refers to problems with the ear structures. There are three types of peripheral hearing loss:

  • Conductive hearing loss, the most common type in children, occurs when the transmission of sound through the external or middle ear is blocked. The condition can be temporary or permanent, and can occur in one or both ears. Sometimes this type of hearing loss is caused by physical abnormalities that are present from birth. More commonly, it begins during childhood as the result of middle ear infections (otitis media). Other causes include perforation of the eardrum, impacted earwax or objects in the ear canal.

  • Sensorineural hearing loss involves problems with the transmission of sound information from hair cells deep within the ear to the nerve that sends sound information to the brain. It is a permanent condition that usually affects both ears. Sensorineural hearing loss can be present at birth, or occur later in life. Causes include prolonged exposure to loud noise, infection (for example, bacterial meningitis), severe head injury, toxic medications and some rare inherited diseases.

  • Mixed hearing loss is both conductive and sensorineural.

Hearing loss is measured by the volume of sounds that can be heard without amplification. Typically, it is classified as borderline or slight, mild, moderate, severe or profound. The term "deaf" generally applies to a person whose hearing loss is so extensive that he or she cannot communicate with another person using only voice.