Hearing Loss in Babies

Milestones Related to Hearing                                                     Different Types of Hearing Loss
Age-Appropriate Speech & Language Milestones                           Different Types of Hearing Tests
Signs of Problems in Speech, Language, & Hearing Development

According to the National Institutes of Health (NIH), nearly 12,000 babies are born each year in the United States with a hearing impairment. Approximately 200 babies with significant hearing loss are born each year in Wisconsin. 

It is estimated that serious hearing loss occurs in about one to three of every 1,000 healthy newborns, and in two to four of every 100 babies in newborn intensive care units.

Without screening or testing, hearing loss may not be noticed until the baby is more than 1 year old. 

If hearing loss is not detected until later years, there will not be stimulation of the brain's hearing centers. This can affect the maturation and development of hearing, and can delay speech and language. Social and emotional development and success in school may also be affected. 

Drs Firszt, Kerschner, and Wackym have played an important role in helping get a law passed in Wisconsin to mandate hearing screening for all newborns. 

Drs. Kerschner and Firszt have also helped play a key role in the implementing of statewide programs to screen babies for hearing loss, and continue to serve on the State's Taskforce for Universal Newborn Hearing Screening to implement intervention programs for children identified with hearing loss at birth. 

Drs. Firszt and Wackym lead the most comprehensive early intervention program, including cochlear implantation, in the states of Wisconsin, Illinois, and Iowa.

Most hearing loss is congenital (present at birth), but some babies develop hearing loss after they are born. Hearing loss is more likely in premature babies and babies with respiratory problems who have required long-term use of breathing machines, those with previous infections, and those taking certain medications.

Because of these risks, many health organizations including the National Institutes of Health (NIH) and the American Academy of Pediatrics (AAP) also recommend universal infant hearing screening. This means all newborn babies should be screened for hearing loss. 

With new hearing tests, a child's hearing can be tested at any age. Through the leadership of Drs. Firszt and Wackym, new methods of testing the hearing of infants are being developed at the Medical College of Wisconsin and the Children's Hospital of Wisconsin.

Milestones Related to Hearing

Birth to 3 months:

• Reacts to loud sounds with startle reflex
• Is soothed and quieted by soft sounds
• Turns head to you when you speak
• Is awakened by loud voices and sounds
• Seems to know your voice and quiets down, if crying 

• Looks or turns toward a new sound
• Responds to "no" and changes in tone of voice
• Imitates his/her own voice
• Enjoys rattles and other toys that make sounds
• Begins to repeat sounds (such as ooh, aah, and ba-ba)
• Becomes scared by a loud voice or noise

• Responds to his/her own name, telephone ringing, someone's voice, even when not loud
• Knows words for common things (cup, shoe) and saying ("bye-bye")
• Makes babbling sounds, even when alone
• Starts to respond to requests such as "come here"
• Looks at things or pictures when someone talks about them

• Plays with own voice, enjoying the sound and feel of it
• Points to or looks at familiar objects or people when asked to do so
• Imitates simple words and sounds; may use a few single words meaningfully
• Enjoys games like peek-a-boo and pat-a-cake
• Follows one step commands when shown by a gesture

• Follows simple directions, such as "give me the ball" without being shown
• Uses words he/she has learned often
• Uses 2 to 3 word sentences to talk about and ask for things
• Knows 10 to 20 words
• Points to some body parts when asked

• Understands simple "yes-no" questions (Are you hungry?)
• Understands simple phrases ("in the cup," "on the table")
• Enjoys being read to
• Points to pictures when asked
• Knows 50 to 100 words 

• Understands "not now" and "no more"
• Chooses things by size (big, little).
• Follows two step commands, such as "get your shoes and come here"
• Understands many action words (run, jump)

• Coos
• Vocalizes pleasure and displeasure sounds (laughs, giggles, cries, or fusses)
• Makes noise when talked to 

• Understands "no-no"
• Babbles (says "ba-ba-ba") 
• Says ma-ma or da-da without meaning 
• Tries to communicate by actions or gestures
• Tries to repeat your sounds
• Says first word 

• Answers simple questions nonverbally
• Says two to three words to label a person or object (pronunciation may not be clear)
• Tries to imitate simple words
• Vocabulary of four to six words 

• Correctly pronounces most vowels and n, m, p, h, especially in the beginning of syllables and short words - also begins to use other speech sounds
• Vocabulary of 50 words, pronunciation is often unclear
• Asks for common foods by name
• Makes animal sounds such as "moo"
• Starting to combine words such as "more milk"
• Begins to use pronouns such as "mine"
• Uses two word phrases 

• Knows some spatial concepts such as "in," "on"
• Knows pronouns such as "you," "me," "her"
• Knows descriptive words such as "big," "happy"
• Vocabulary of 250 to 900 words
• Uses three word sentences
• Knows 50-100 words
• Speech is becoming more accurate but may still leave off ending sounds - strangers may not be able to understand much of what is said
• Answers simple questions
• Begins to use more pronouns such as "you" or "I"
• Uses question inflection to ask for something such as "my ball?"
• Begins to use plurals such as "shoes" or "socks" and regular past tense verbs such as "jumped"

• Groups objects such as foods, clothes, etc.
• Identifies colors
• Uses most speech sounds but may distort some of the more difficult sounds such as l, r, s, sh, ch, y, v, z, th - these sounds may not be fully mastered until age 7 or 8
• Uses consonants in the beginning, middle, and ends of words - some of the more difficult consonants may be distorted, but attempts to say them
• Strangers are able to understand much of what is said
• Able to describe the use of objects such as "fork," "car," etc.
• Has fun with language - enjoys poems and recognizes language absurdities such as, "is that an elephant on your head?"
• Expresses ideas and feelings rather than just talking about the world around him/ her
• Uses verbs that end in "ing," such as "walking" and "talking"
• Answers simple questions such as "What do you do when you are hungry?"
• Repeats sentences

• Understands spatial concepts such as "behind," "next to"
• Understands complex questions
• Speech is understandable but makes mistakes pronouncing long, difficult, or complex words such as "hippopotamus" 
• Vocabulary of about 1500 words
• Uses some irregular past tense verbs such as "ran," "fell"
• Describes how to do things such as painting a picture
• Defines words
• Lists items that belong in a category such as animals, vehicles, etc.
• Answers "why" questions 

• Understands more than 2,000 words 
• Understands time sequences (what happened first, second, third, etc.)
• Carries out a series of three directions
• Understands rhyming
• Engages in conversation
• Sentences can be eight or more words in length
• Uses compound and complex sentences
• Describes objects
• Uses imagination to create stories 

• No response to sound at any age 
• Infant does not move or jump when a loud sound is made
• No babbling by the time the infant is 9 months old
• No words spoken by the age of 18 to 24 months
• Does not follow simple commands by 2 years old
• Poor voice quality at any age 

• Congenital factors - conditions present at birth or develop during childhood.
  • Genetic factors and syndromes the child has at birth
  • Infection by the mother with toxoplasmosis, rubella, cytomegalovirus, herpes, or syphilis
  • Low birthweight 
  • Hereditary - in the family
• Acquired
  • Loud noise exposure
  • Trauma
  • Infections
  • Damage from certain medications that can be harmful to the ears
  • Tumors
  • Perilymph fistula (fluid leakage from inner ear)

Conductive hearing loss - a problem in the outer ear, ear canal, or middle ear where sound waves are not sent to the inner ear correctly. Conductive hearing loss is the most common type of hearing loss in children and is usually acquired. Factors that may cause this type of hearing loss are: 

• Congenital factors - conditions present at birth
  • Anomalies of the pinna (the outside of the ear)
  • Anomalies of the tympanic membrane (eardrum)
  • Anomalies of the external ear canal
  • Anomalies of the ossicles (the three tiny bones that deliver the sound waves to the middle ear 
  • Anomalies of the middle ear (congenital cholesteatoma)
• Acquired 
  • Ear infections such as otitis media
  • Chronic ear infections with fluid in the middle ear
  • Excessive ear wax 
  • Foreign bodies in the ear canal
  • Tumors of the middle ear (e.g., cholesteatoma)
  • Problems with the eustachian tube
  • Perforation of the eardrum 

Hearing tests for the newborn: There are two primary types of hearing screening methods for newborns. These may be used alone or together.

• Evoked otoacoustic emissions (EOAE) - a test that uses a tiny, flexible plug that is inserted into the baby's ear. Sounds are sent through the plug. A microphone in the plug records the otoacoustic emissions (responses) of the normal ear in reaction to the sounds. There are no emissions in a baby with hearing loss. This test is painless and is usually completed within a few minutes, while the baby sleeps. 
• Auditory brainstem response (ABR) - a test that uses electrodes (wires) attached with adhesive to the baby's scalp. While the baby sleeps, clicking sounds are made through tiny earphones in the baby's ears. The test measures the brain's activity in response to the sounds. As in EOAE, this test is painless and takes only a few minutes. 
• Steady state evoked potentials (SSEP) - Children of all ages may be tested with the SSEP test.

If the screening tests identify that your child has a hearing loss, further testing is needed. It is recommended that all babies with hearing loss be identified by 3 months of age so that treatment can begin before the baby is 6 months old, an important time for speech and language development. 

Hearing tests for the infant: Evaluation of hearing in the infant may include the use of the above mentioned EOAE and ABR tests. Also, the following may be used:

• Behavioral audiometry - a screening test used in infants to observe their behavior in response to certain sounds. Additional testing may be necessary. 

Hearing tests for the toddler: Evaluation of hearing may include the above mentioned tests, along with the following:

• Play audiometry - a test that uses an electrical machine to transmit sounds at different volumes and pitches into your child's ears. Your child usually wears some type of earphones. This test is modified slightly in the toddler age group and made into a game. The toddler is asked to do something with a toy (i.e., touch a toy, move a toy) every time the sound is heard. This test relies on the cooperation of the child, which may not always be given. 

Hearing tests for the older child:  Evaluation of hearing for the child older than 3 to 4 years may include the above mentioned tests, along with the following:

• Pure tone audiometry - a test that uses an electrical machine that produces sounds at different volumes and pitches in your child's ears. The child usually wears some type of earphones. In this age group, the child is simply asked to respond in some way when the tone is heard in the earphone. 
• Tympanometry (also called impedance audiometry) - a test that can be performed in most physician offices to help determine how the middle ear is functioning. It does not tell if the child is hearing or not, but helps to detect any changes in pressure in the middle ear. This is a difficult test to perform in younger children because the child needs to sit very still and not be crying, talking, or moving.