Symptoms:

Signs of hearing loss in infants vary by age. For example:

• A newborn baby with hearing loss may not startle when a loud noise sounds nearby.
• Older infants, who should be responding to familiar voices, may show no reaction when spoken to.
• Children should be using single words by 15 months, and simple 2-word sentences by age 2. If they do not reach these milestones, hearing loss since infancy may be the cause.

Some children may not be diagnosed until they are in school. This is true even if they were born with hearing loss. Inattention and falling behind in class work may be the result of an undiagnosed hearing loss problem.

Signs and tests:

Hearing loss results in a baby's inability to hear sounds below a certain level. A baby with normal hearing will hear sounds below that level.

The health care provider will examine your child. The exam may show problems such as bone problems or signs of genetic changes that may cause hearing loss.

The doctor will use an instrument called an otoscope to see inside the baby's ears. This allows the doctor to see the eardrum and detect several problems that may cause conductive hearing loss.

Two common tests are used to screen newborn infants for hearing loss:

• Auditory brain stem response (ABR) test. This test uses patches, called electrodes, to determine how the auditory nerve reacts to sound.
• Otoacoustic emissions (OAE) test. Microphones placed into the baby's ears detect nearby sounds. The sounds should echo in the ear canal. If there is no echo, it is a sign of hearing loss.

Older babies and young children can be taught to respond to sounds through play. These tests, known as visual response audiometry and play audiometry, can better determine the child's range of hearing.