Listen up, parents: Screening babies for hearing loss is a top priority since normal hearing is needed (at least initially) for children to understand—and later produce—spoken language.

Because of this, your baby’s hearing is on your pediatrician’s radar from day one. In fact, hearing tests are a standard element of newborn screenings, with many states automatically testing babies’ hearing before they’re discharged after birth. (Find out if your state conducts newborn hearing tests at birth.) If the test is not done before you take your precious bundle home, schedule it within 30 days at the pediatrician’s office.

In addition to newborn hearing screenings, it’s important for you trust your gut if you have any concerns around your baby’s ability to hear. If you suspect something’s not right, reach out to your baby’s physician for a formal hearing evaluation. The good news is, hearing issues can not only be identified early by regular monitoring, but can be treated early, too. 

Of course, before you can spot issues, you’ll need to learn what developmental hearing milestones you can expect­—and when.  Here’s what you need to know…

Normal Hearing Milestones for Babies

All babies develop at slightly different rates, but here are some hearing benchmarks that babies are expected to reach during their first year.

Birth to 3 Months Hearing Milestones

  • Reacts to loud noises with startle reflex

  • Wakes up to loud noises

  • Responds to soft shushing sounds

  • Calms down or smiles when spoken to

  • Stops crying or quiets down when they hear your voice

  • Turns head to you when you speak

4 to 6 Months Hearing Milestones

  • Turns head toward a new sound

  • Responds to changes in the tone of your voice

  • Enjoys toys that make sound

  • Imitates own voice

  • Begins to repeat sounds such as “ooh” and “bah”

  • Startles or seems scared of loud noises

  • Responds to “No”

7 to 12 Months Hearing Milestones

  • Responds to own name, the phone ringing, and other’s voices

  • Begins to respond to requests

  • Babbles

  • Imitates simple words and sounds, such as “Mama,” “Dada,” or “hi”

  • Understands words for common items and actions, like “cup,” “shoe,” and “bye-bye”

  • Looks at objects or pictures when someone talks about them

  • Enjoys games like peek-a-boo and pat-a-cake

Baby Hearing Basics

The auditory system is what helps your sweetie hear sounds. It’s composed of brain regions and the ear itself, which is made up of three different sections: the outer, middle, and inner ear. 

  • Outer ear: The mostly visible part, which includes the ear canal and the side of the eardrum that a doctor can see with an otoscope

  • Middle ear: Located behind the eardrum, the middle ear and contains three small bones that move when the eardrum vibrates from sound coming in. These bones move sound to the inner ear. 

  • Inner ear. This part of the ear helps with balance and changes vibrations into signals that travel to the brain. The inner ear houses the auditory nerve (also called the cochlear nerve), which sends incoming sound info to the brain. 

Common Causes of Hearing Problems in Babies

About 1% of babies in the U.S. are born with hearing loss, dubbed congenital hearing loss. Oftentimes, congenital hearing loss means there is a family history of hearing loss. Other causes of hearing loss include:

  • Born prematurely

  • Low birth weight (less than 5 pounds, 8 ounces)

  • Birth defect that altered the shape or structure of Baby’s head, face, or ears

  • Gestational diabetes

  • Infections or viruses during pregnancy such as rubella or herpes simplex virus

  • Fetal alcohol syndrome

  • Genetic cause, such as Down syndrome or Usher syndrome (About 1 out of 3 babies with genetic hearing loss have a “syndrome.”)

According to the March of Dimes, head injury, contracting meningitis or measles, severe jaundice, or certain medications can also cause hearing issues in some babies. Whether congenital or acquired, early hearing loss detection is key.

Common Hearing Problems in Babies

Hearing loss can range from mild (sounds might be softer than they should be) to moderate to severe…all the way to profound (no speech sounds can be heard). Here are some more specifics on the different types of hearing issues that can impact babies:

Conductive Hearing Loss

Conductive hearing loss is the most common cause of hearing loss in young children. Here, sound waves can’t freely pass through the outer or middle ear, making it hard to hear soft sounds and/or louder sounds can seem muffled. There are many reasons why conductive hearing loss can occur, including:

  • Wax build-up in ear canal

  • Fluid in middle ear due to a cold or allergies

  • Ear infection (otitis media or external otitis, aka swimmer’s ear)

  • Certain birth defects, including being born without an outer ear

  • Ruptured or scarred eardrum

  • Foreign object stuck in ear 

  • Fluid build-up in middle ear

  • Benign tumors

Sensorineural Hearing Loss

When the inner ear (cochlea) or nerve endings that move sound through the ear aren’t working properly, sound signals can’t travel to your little one’s brain. This type of hearing loss is called sensorineural hearing loss, and it often permanent. Again, soft sounds are likely hard to hear and/or louder sounds can seem muffled. There are two types of sensorineural hearing loss (also called nerve deafness): Congenital, meaning your baby was born with hearing loss, and acquired sensorineural hearing loss that develops later. Causes of sensorineural hearing loss include:

  • Infection during pregnancy. Being infected with toxoplasmosis, rubella, herpes, syphilis, or cytomegalovirus (CMV) during pregnancy increases the odds that Baby will experience hearing loss. In fact, 14% of babies exposed to CMV during pregnancy develop sensorineural hearing loss.

  • Malformation of the inner ear. Malformations in the inner ear, vestibulocochlear nerve, or the auditory cortex of brain can lead to congenital sensorineural hearing loss.

  • Genetics. Parents with hearing loss are more likely to have children with hearing loss.

  • Premature birth. Research shows that the risk of hearing loss in preemies is substantially higher than in the general newborn population

  • Low birth weight. The risk of hearing loss is greatest in children weighing less than 3.3 pounds at birth.

  • Medication. Certain drugs, such as aminoglycoside antibiotics and the chemotherapy drug cisplatin ototoxicity.

  • Viral infections. Contracting infections such as measles, rubella, meningitis, and mumps can increase the chance of hearing loss.

Auditory Neuropathy Spectrum Disorder (ANSD)

Technically, auditory neuropathy spectrum disorder (ANSD) falls under the umbrella of sensorineural hearing loss. Here, sound enters the ear just fine, but there’s a hiccup when it comes to sending those sound waves to the brain. (ANSD accounts for 10 to 15% of all hearing loss cases and most babies who have ANSD are diagnosed within their first few months of life. Some kiddos with ANSD can hear sound, but they can’t distinguish what those sounds are. For others, all sounds are perceived as white noise. While ANSD can get worse over time, it may get better or remain stable. So far, the cause is a mystery, but here are some suspected contributing factors:

  • Born before 28 weeks

  • Low birth weight

  • Family history of ANSD

  • Severe jaundice

  • Head trauma

  • Congenital brain abnormalities

  • Lack of oxygen at birth

  • Various viruses, including as measles, mumps, cytomegalovirus, (CMV) and HIV

Mixed Hearing Loss

Your baby could have both conductive and sensorineural hearing loss, which means there’s likely damage to the outer or middle ear and the inner ear or the nerve pathway to the brain. This is called mixed hearing loss

Unilateral Hearing Loss

Unilateral hearing loss, or UHL, is hearing loss in only one ear. This type of hearing loss is also called also called single-sided deafness (SSD) and it can occur with both sensorineural hearing loss and conductive hearing loss. Between 3 and 6% of school-aged children have unilateral hearing loss. Even though children with UHL can hear out of one ear, research shows that they may still exhibit speech and language delays.

How to Spot Hearing Problems in Babies

Any problems with hearing should be addressed with your baby’s pediatrician or another healthcare provider, such as an audiologist or an otolaryngologist (also called an ENT), as soon as possible. Continue to pay attention to when (and if) your child hits their hearing milestones (above), keeping the following red flags top of mind:

  • Does not startle with loud noises by 1 month

  • Does not turn to the source of a sound by 3 to 4 months old

  • Speech is delayed or difficult to understand

  • Doesn’t say any words like "Mama" or "Dada" by 12 to 15 months

  • Doesn’t respond when you call their name out of their line of sight 

  • Seems to hear some sounds but not others

  • Has trouble holding head steady, along with hearing issues

  • Slow to sit or walk unsupported, along with hearing issues

Know that if your baby seems to be slow to achieve certain hearing milestones, it doesn’t necessarily indicate they have a hearing loss. What it does indicate: You’ve got something you should share with your baby’s doctor, so that your little one can be evaluated further. After all, the sooner your baby’s hearing is tested, the sooner you and your baby’s care team can come up with a treatment plan, if needed.

More on Hearing and Speech:

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REFRENCES

  • The Centers for Disease Control and Prevention (CDC): Newborn Hearing Screening
  • Children’s Hospital of Philadelphia: Age-Appropriate Speech and Hearing Milestones
  • StatPerals: Neuroanatomy, Auditory Pathway
  • CDC: Parts of the Ear
  • UCSF Health: Ear examination
  • March of Dimes: Hearing loss and your baby
  • Comparison of hearing screening outcomes in newborns of gestational diabetic and non-diabetic mothers: a prospective, controlled study. Journal of Maternal-Fetal and Neonatal Medicine. December 2022
  • CDC: Basics about FASDs
  • CDC: What is Hearing Loss in Children?
  • Boston Children’s Hospital: What is hearing loss?
  • American Speech-Language-Hearing Association (ASHA): Conductive Hearing Loss
  • ASHA: Sensorineural Hearing Loss
  • Boston Children’s Hospital: What is sensorineural hearing loss?
  • CDC: Data and Statistics About Hearing Loss in Children
  • Radiological diagnosis of the inner ear malformations in children with sensorineural hearing loss, BJR Open, June 2019
  • Hearing impairment in premature newborns—Analysis based on the national hearing screening database in Poland, PLOS One, September 2017
  • Hear-it.org: Low birth weight increases risk of hearing loss
  • Hear-it.org: Medicines can cause hearing loss
  • Viral Causes of Hearing Loss: A Review for Hearing Health Professionals, Trends in Hearing, July 2014
  • National Organization for Rare Disorders (NORD): Auditory Neuropathy Spectrum Disorder
  • Nemours Children’s Health, KidsHealth: Auditory Neuropathy Spectrum Disorder (ANSD)
  • Nemours Children’s Health, KidsHealth: Hearing Loss
  • Hear-it.org: Unilateral hearing loss and single sided deafness
  • Cleveland Clinic: A Closer Look at Unilateral Hearing Loss in Pediatric Patients
  • Speech and Language Consequences of Unilateral Hearing Loss: A Systematic Review, Otolaryngology–Head and Neck Surgery, August 2017
  • American Academy of Pediatrics (AAP): Hearing Loss in Children

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.