Common Causes and Types of Hearing Loss

Some children are born with hearing loss that runs in the family. This kind of hearing loss can happen even if no one else in the family is deaf or hard of hearing. Genes can be passed down from parents—even if the parents hear fine. Learn more about genetic causes of hearing loss from the CDC.

CMV is a common virus that most people do not even know they have. But if a baby is infected before birth, it is called congenital CMV. It can cause hearing loss and other disabilities.

• Hearing loss from CMV might be present at birth or may show up months or even years later.
• It can affect one or both ears and may get worse over time.
• Some babies with congenital CMV show signs at birth (like a small head, rash, or low birth weight), while others appear healthy but still develop hearing loss later.

Good to know: Babies can be tested for CMV within the first few weeks of life. Early treatment and monitoring can make a difference.

Sometimes the inner ear does not form the typical way during early pregnancy. This may be called an inner ear abnormality, deformation, or malformation, and it can cause hearing loss from birth.

• These malformations can include problems with parts of the inner ear such as, inner ear bones, cochlea (the hearing organ), the auditory nerve, or the vestibular system (which helps with balance).
• Some children with malformations may also have balance issues or delays in walking.
• Inner ear malformations are often found through imaging tests like an MRI or CT scan.

Other infections during pregnancy such as rubella (German measles), toxoplasmosis, or sexually transmitted diseases, can also affect how the baby’s ears or brain develop. These may lead to hearing loss that is present at birth or becomes noticeable later.

Babies who are born early or who had a difficult birth may be more likely to have hearing loss. This might be due to a lack of oxygen, jaundice, or medications used in the NICU.

Serious illnesses after birth like meningitis, measles, or frequent ear infections, can damage parts of the ear or the hearing nerve. Hearing loss from these infections can be permanent and may happen suddenly.

Long or repeated exposure to loud sounds—even in children—can damage hearing over time. This is called noise-induced hearing loss. It is more common in older children and teens who use headphones at high volumes or attend loud events without protection.

Some medicines used to treat serious illness can affect hearing. These are called ototoxic drugs. Children who need certain treatments for cancer, infections, or other health conditions may need regular hearing tests to watch for changes.

In some cases, we do not know the exact reason for a child’s hearing loss. This is called idiopathic. Even when the cause is unknown, there are still many ways to support your child’s learning and communication.

• What it means: Sound has trouble moving through the outer or middle ear.
• Possible causes include: Earwax blockages, fluid from ear infections, or a problem with the eardrum tiny ear bones, or malformed outer ear.
• Good to know: This type is often temporary or treatable with medicine, surgery, or hearing aids.

• What it means: The inner ear or hearing nerve is not working as it should.
• Causes include: Genetic conditions, family history, head trauma, how the inner ear was formed, infections like CMV or meningitis, or loud noise exposure.
• Good to know: This type is usually permanent. Children with sensorineural hearing loss often benefit from hearing aids or cochlear implants.

• What it means: This type of hearing loss is a mix of two kinds—conductive (middle ear) and sensorineural (inner ear).
• Possible causes: A child may have more than one condition affecting their hearing. For example, fluid or repeated ear infections can cause middle ear problems, while differences in how the inner ear developed, or damage to the inner ear, can cause sensorineural loss. Sometimes both happen together, which leads to mixed hearing loss.
• Good to know: Treatment depends on which parts of the ear are affected. Doctors may use a mix of medical care, surgery, and hearing technology to help.

• What it means: Sound enters the ear normally, but the signal does not reach the brain clearly.
• Causes include: Prematurity, jaundice, genetic conditions, or unknown reasons.
• Good to know: Children with ANSD may have hearing that changes over time. They may benefit from cochlear implants, sign language, or other supports.