What is the latest age that hearing loss should be detected to ensure that a child achieves normal language development?

If your baby or child has recently been diagnosed with hearing loss, you likely have a lot of questions and concerns. It's normal to feel overwhelmed and anxious, but rest assured that there are many treatment and adaptation options available, for both home and school. 

and a pediatric audiologist. 

Perhaps the most important thing to know is that hearing ability helps a child develop her speech and language skills. It's critical to make sure your child's hearing loss is treated appropriately, to reduce the impact that hearing loss has on her education.

In fact, research shows that treating hearing loss before a baby reaches six months of age results in significantly better speech and language outcomes than treating later. Research also shows that hearing aids boost school performance in children who have hearing loss.

What is childhood hearing loss?

A child may be diagnosed with hearing loss if they can't hear sounds below a certain level of volume, depending on the hearing test results, in either one ear (known as unilateral) or both ears (bilateral). The most minimal threshold is usually somewhere around 15 to 20 decibels (dB) of sound, which is roughly the sound of leaves rustling or people whispering.

Even though being unable to hear leaves rustling would be considered a slight degree of hearing loss, it will make it harder to understand certain parts of speech. That's why treating hearing loss is so critical in kids, who are learning language from the moment they are born.

That's a starting point, though. Some children will have mild hearing loss (they can't hear sounds below 25-40 dB), moderate (41-60 dB), severe (61-80 dB) and profound (81+ dB). Being unable to hear virtually all sound is known as profound deafness.

It's not just a matter of volume

Hearing loss is a combination of loss of volume (measured in decibels) and loss of pitch, or frequency (measured in Hertz). For example, some children may struggle to hear sounds that are high-pitched, but have no problem hearing low-pitched sounds, known as high-frequency hearing loss. A child who has moderate hearing loss in the high frequencies will be unable to hear most speech correctly, but may hear a helicopter miles away with no problem.

Some may have the reverse, which is low-frequency hearing loss, and others will have what's known as "flat" hearing loss, which means they struggle to hear sounds across all pitches, from low to high. As you can see, hearing loss is unique and highly variable, which is why customized hearing aids are extremely important, since they can be adjusted to a child's specific pattern of hearing loss. 

To fully understand your child's hearing loss, it's important to know the degree of hearing loss in each ear, as well as what pitches are harder for them to hear.

Hearing loss at a young age

How common is hearing loss in kids?

There are many different estimates depending on the organization gathering the data, but overall hearing loss is fairly common in kids. One national survey estimated that about 15% of kids and teens have hearing loss, though in most cases the hearing loss was slight, and in only one ear. More severe levels of hearing loss are less common.

Signs and symptoms of hearing loss in babies

Hospitals routinely perform newborn hearing screening on infants in the first day or two after birth. If a a newborn shows signs of infant hearing loss, he or she is usually scheduled for a second screening a few weeks later. However, sometimes newborns who pass both hearing screenings may exhibit signs of hearing loss as they get older.

If you think your child is having difficulty hearing you, visit your pediatrician right away.

One way to determine if your child’s hearing is developing appropriately is by monitoring important speech and hearing milestones, such as these from the American Speech Language Hearing Association:

Babies and infants

From birth to four months, your infant should:

• Startle at loud sounds
• Wake up or stir at loud noises
• Respond to your voice by smiling or cooing
• Calm down at a familiar voice

From four months to nine months, your infant should:

• Smile when spoken to
• Notice toys that make sounds
• Turn its head toward familiar sounds
• Make babbling noises
• Understand hand motions like the bye-bye wave

From nine to 15 months, your baby should:

• Make various babbling sounds
• Repeat some simple sounds
• Understand basic requests
• Use its voice to get your attention
• Respond to name

From 15 to 24 months, your toddler should:

• Use many simple words
• Point to body parts when you ask
• Name common objects
• Listen with interests to songs, rhymes and stories
• Point to familiar objects you name
• Follow basic commands

Signs of hearing loss in toddlers and school-age children

Older children sometimes develop hearing loss that wasn't present before. Here are some things to look for if you think your toddler or preschool-age child might have hearing loss:

• Your child is being flagged for a learning disorder or ADHD—always make sure they get a hearing loss screening, too, since hearing loss can mimic learning disorders and behavioral conditions.
• Has difficulty understanding what people are saying.
• Speaks differently than other children her or his age.
• Doesn't reply when you call his or her name.
• Responds inappropriately to questions (misunderstands).
• Turns up the TV volume incredibly high or sits very close to the TV to hear.
• Has problems academically, especially if they weren't present before.
• Has speech or language delays or problems articulating things.
• Watches others in order to imitate their actions, at home or in school.
• Complains of ear pain, earaches or noises.
• Cannot understand over the phone or switches ears frequently while talking on the phone.
• Says "what?" or "huh?" several times a day.
• Watches a speaker's face very intently—many children's hearing loss escapes detection because they are very successful lip readers.

More: What to do if you suspect your school-age child has hearing los

What caused my child's hearing loss?

When a child is born with hearing loss

Some babies are born with hearing loss, which is known as congenital hearing loss. Many different things can cause this type of hearing loss, but it's not always possible to pinpoint the precise cause. In about half of all cases, the cause is genetic—meaning, inherited from a parent. 

Genetic factors cause more than 50 percent of all hearing loss in children, whether present at birth or developed later in life.

Genetic factors that might cause congenital hearing loss include:

• Autosomal recessive hearing loss - This is the most common type of genetic congenital hearing loss, accounting for about 70 percent of all genetic hearing loss cases. What this means is that neither parent has a hearing loss, but each parent carries a recessive gene that gets passed to the child. Parents are usually surprised when their child is born with this type of hearing loss because people typically aren't even aware they have the recessive gene.
• Autosomal dominant hearing loss - This type of hearing loss accounts for around 15 percent of genetic hearing losses, according to the American Speech-Language-Hearing Association (ASHA). In autosomal dominant hearing loss, one parent carrying a dominant gene for hearing loss passes it to the offspring. This parent may or may not have hearing loss, but he or she might have other symptoms or signs of a genetic syndrome.
• Genetic syndromes - These include Usher syndrome, Treacher Collins syndrome, Waardenburg syndrome, Down syndrome, Crouzon syndrome and Alport syndrome. More on rare diseases and hearing loss. 

Non-genetic factors that might cause congenital hearing loss include:

• Birth complications, including herpes, rubella cytomegalovirus, toxoplasmosis or another serious infection; lack of oxygen; or the requirement of a blood transfusion for some reason.
• Premature birth. Babies that have a birth weight of less than 3 pounds or that require certain life-sustaining drugs for breathing due to prematurity are at increased risk for hearing loss.
• A nervous system or brain disorder.
• The use of drugs that cause hearing loss by the mother during pregnancy. Known as ototoxic medications, these drugs are usually prescribed medications, including antibiotics and some pain relievers. Ototoxic drugs potentially cause damage to the auditory nerve or other hearing structures in a fetus.
• The mother had an infection during pregnancy, including diseases like toxoplasmosis, cytomegolavirus, herpes simplex or German measles.
• Maternal diabetes.
• Drug or alcohol abuse by the mother or smoking during pregnancy. 

These non-genetic factors account for only around 25 percent of congenital hearing loss. For the remaining 25 percent, no cause can be found. 

When a child develops hearing loss later

Children can also be affected by acquired hearing loss, meaning it occurs at any point after birth. There are various causes of acquired hearing loss, including:

• A perforated eardrum
• Otosclerosis or Meniere's disease
• Infections like meningitis, measles, mumps or whooping cough
• Taking medications linked to hearing loss (see above)
• A serious head injury
• Exposure to loud noise, causing noise-induced hearing loss
• Untreated or frequent otitis media (ear infections)
• Exposure to secondhand smoke or other toxins

Sometimes, the cause of the hearing loss is temporary, such as these four common causes of temporary hearing loss in kids. 

Auditory processing disorder in kids with normal hearing

Some kids may pass traditional hearing tests, but still struggle to listen and understand speech, particularly in noisy environments. They may ask you to repeat what you've said a lot, and struggle to differentiate similar sounding words. If this sounds like your child, it's important to talk to your doctor, as it could be auditory processing disorder. This means the ears can detect sound adequately, but the brain struggles to interpret the sound correctly. 

Temporary hearing loss in children

Some children may experience hearing loss that comes and goes, known as temporary, transient or fluctuating hearing loss. Even though it may not be lifelong, this kind of hearing loss is still harmful to speech and language development. Transient hearing loss can be caused by otitis media, more commonly known as a middle ear infection. One out of every 4 kids have had one episode of otitis media by the time they are three years old. This type of infection is very common in children because of the Eustachian tube position during childhood. The Eustachian tube, which allows for air pressure equalization between the middle ear and the nasopharynx, is smaller and more horizontal during development. Thus, it is very susceptible to blockage by fluids or large adenoids (glands in the throat area).  

A middle ear infection can cause transient hearing loss because excess fluids in the keep the tiny middle ear bones from working properly. Thankfully, this type of hearing loss is usually temporary and resolves itself. However, frequent, untreated middle ear infections can cause cumulative damage to the bones, eardrum or auditory nerve, creating a permanent, sensorineural hearing loss.

Hearing tests for children

Newborn hearing screenings

Newborn hearing screening is mandated across all 50 states, requiring that newborn babies have their hearing screened before leaving the hospital. There are two types of newborn hearing screenings, both are painless and can be done while the baby sleeps. Read more about newborn hearing screening.

Hearing testing for babies, toddlers and kids

Infant hearing testing: Visual reinforcement audiometry

Pediatric audiologists can test infants as young as six months of age behaviorally in a sound-treated booth using a test called visual reinforcement audiometry (VRA). VRA takes advantage of an infant’s reflexive head turn toward sound. In this test, a parent will hold their child on their lap while they sit on a chair in the center of the sound booth. The audiologist will play sounds or talk through speakers that are oriented to the left and right of the child.

When the child hears the sound and looks toward it, he or she is rewarded with a visual reinforcement toy like a flashing light or dancing bear. The infant will usually stay engaged long enough for the audiologist to get a good indication of hearing ability for at least the better hearing ear.

The visually-appealing toys lose their ability to hold the child’s attention once they are toddlers. Around the age of two, social praise will work for behavioral testing.

Toddler hearing tests: Play audiometry

A pediatric audiologist will use a method of testing called play audiometry for toddlers and preschool children. It's a hearing test that is made into a game for toddlers. The parent or assistant will sit on the floor in the booth with the child and train them to respond to any sound they hear by doing a certain task, like putting a block in a bucket.

When the child correctly responds to a sound, the parent or assistant sitting with them will cheer with enthusiasm. Like the visual reinforcement described above, this age-appropriate social reinforcement will typically keep the child engaged long enough for the audiologist to get a good indication of hearing ability at least for the better hearing ear. If the toddler will wear earphones, ear-specific information can be obtained.

Hearing tests for kids

Once a child is school-aged, he or she can usually sit still, remain quiet and raise a hand in response to speech and tone stimuli in the sound booth. At this point, the child can easily wear headphones for ear-specific measurements and sit still for tympanometry and acoustic reflex tests, similar to adult hearing tests. 

Treatments for childhood hearing loss

Depending on the severity and cause of hearing loss in your child, hearing aids, cochlear implants and a combination of speech therapy or assistive listening devices might be recommended forms of treatment. If you notice that your infant or child shows any of the above signs, take him or her to your family doctor, who can refer you to a pediatric audiologist to have your child's hearing tested. If a child has wax buildup, an ear infection or another problem causing temporary hearing loss, the audiologist will take care of the problem or refer you to an otolaryngologist (ear, nose and throat physician) to have the temporary hearing obstruction treated.

There has never been more hope for children with hearing loss, even those with severe hearing loss.

Audiologists can perform in-depth behavioral hearing examinations for even very young children (as young as 6 months). There are several objective tests that infants, toddlers and young children can undergo as well. These tests are painless and non-invasive. After the exam, the audiologist will spend time talking with you about your child's hearing ability and recommend an appropriate treatment plan or medical intervention.

Hearing aids

Hearing aids are just one kind of device that can help children with hearing loss hear clearly again. There are many pediatric hearing aids, including high-powered aids for children with profound hearing loss that offer high-quality hearing assistance. Many solutions for children include special coverings and other accessories to ensure that young children don't remove or misplace their hearing aids. There are several models of devices to choose from, including behind-the-ear hearing aids or those that are almost entirely in the ear canal and very discreet. 

Cochlear implants

Cochlear implants are surgically implanted devices that directly stimulate the auditory nerve in the inner ear with electrical stimulation. Cochlear implants also have an external device, and many companies make kid-friendly devices that can be held on with a soft headband. Cochlear implants work for infants and children who cannot benefit from hearing aids.

Bone-anchored hearing systems

In some cases, a child may be a better candidate for a bone-anchored hearing system. People who typically get the greatest benefit from bone-anchored hearing systems include those who have severe outer or middle ear malformations, such as microtia and atresia, and those with single-sided deafness.

Speech therapy

For children who have had hearing loss that has affected their speech, he or she might need speech-language therapy after getting hearing aids or a cochlear implant to help him or her catch up on speech delays. Children with auditory processing disorder also can receive therapy to strengthen the way your children understands and uses language. 

Assistive listening devices

Many hearing aid manufacturing companies offer assistive listening devices such as FM systems that are discreet and work well in a classroom situation in conjunction with the child's hearing aid or cochlear implant. FM technology helps overcome the poor acoustics of classroom settings or other venues with lots of background noise. Essentially, the teacher wears or has a discreet microphone in front of him or her that transmits his or her voice directly to the child's hearing aids or cochlear implant.

Hearing loss prevention for youth

You can help your child have a lifetime of healthy hearing by protecting her hearing from loud sounds, including headphones. Noise-induced hearing loss is on the rise in kids and teens. Headphone use in particular is linked to early-onset hearing loss.

School help

Untreated hearing loss negatively affects school performance. Parents aren’t the only ones with a responsibility to make sure certain children with hearing loss have an equal opportunity to learn; schools have responsibilities as well. Most children with hearing loss can be mainstreamed into standard classrooms. An educational audiologist can be an invaluable resource as you navigate your options.

Finding a provider for your child

Seek help right away if you suspect your child has hearing loss. Oftentimes, your pediatrician is a good place to start. She may refer you to a pediatric audiologist or an ear, nose and throat doctor. This primer on different types of hearing specialists may come in handy as you navigate your child's journey to better hearing.