Have you ever wondered about your child's hearing? Parents or other family members are most often the first to recognize a child's hearing difficulties. Since hearing is the primary modality in which young children acquire new information, any suspicion of a hearing loss in your child warrants attention.
The first four years of your child's life are critical in terms of developing speech and language skills that will last a lifetime. Any degree of hearing impairment can be handicapping since hearing loss can negatively impact the acquisition and perception of speech and language, academic achievement, social and emotional development, and self-esteem. Therefore, it is essential to diagnose and treat childhood hearing problems as early as possible.
Are There Speech and Language Milestones in Young Children?
All children develop at their own pace, however there are a few milestones that are helpful when considering whether or not your child might have a hearing problem. They are not steadfast rules but rather guidelines that are helpful in assisting parents and doctors in evaluating your child for a hearing loss. Ask yourself these questions based on your child's age; if your child is having difficulty in any of these areas, it is important for you to bring this to the attention of your child's doctor. It does not necessarily mean that your child has a hearing loss, but it does indicate the need for further evaluation. Unfortunately, hearing loss is invisible, so it is especially important for you to trust your instincts! If you are concerned about a hearing problem in your child, have your child's hearing assessed.
The following are some guidelines to use as a gauge of your child's hearing:
Birth to Three Months:
- Most babies are startled by loud unexpected sounds
- Most children at this age begin to make sounds such as gurgling, babbling, or cooing.
- Most children recognize the sound of their mother's (or primary caregiver's) voice and begin to turn toward the sound of his or her voice at around three or four months. The sound of the primary caregiver's voice will often calm a crying baby, even for a moment.
Three Months to Six Months:
- Babies usually begin to turn their heads toward sources of sounds that originate outside their immediate range of view.
- Infants begin to notice and enjoy musical toys such as bells and rattles.
- At around six months, babies begin babbling in response to someone speaking to them.
Six Months to Nine Months:
- Children begin to respond to their name and understand the concept of the word "No."
- Children make sounds other than cooing and gurgling.
Nine Months to 15 Months:
- Children's voices go up and down when vocalizing sounds.
- Children turn towards a soft noisemaker or when their names are called.
- Children begin to make sounds like "mama" or "dada."
- Music is enjoyable and children often respond to music by "singing" along or bouncing when listening.
Fifteen Months to Two Years:
- Children begin saying at least two other words other than "mama" and "dada."
- Children begin to follow simple two-step commands, such as "Get the ball and bring it to Mommy."
- Children tend to imitate words.
Two Years to Three Years:
- Most children ask questions and tell you what they want.
- Children begin to use pronouns such as "I," "you," and "he or she."
Three to Four Years:
- Children are able to answer simple questions.
- Children begin naming colors and use action words in describing things.
- Children can attempt to describe what is happening in a picture.
- Children begin to understand conversations easily and speak so that others (aside from their primary caregivers) understand them.
Health
Surprisingly, hearing loss is common in children. A recent study in The Journal of the American Medical Association showed that 14.9 percent of school-aged children have some degree of hearing loss. Moreover, approximately one in 800 newborns are born with a congenital hearing loss (a hearing loss that is present at birth). This makes this type of hearing loss one of the most common birth defects found in newborns.
How Do Children Hear?
In order to understand the different types of hearing losses found in children, it is necessary to understand something about how the ear works. The ear is divided into three parts: the external, middle, and inner ear. The external ear is composed of the external auditory canal, the pinna, and the outer surface of the eardrum (or the tympanic membrane). The middle ear is made up of the tympanic membrane and three small bones, the malleus, incus and stapes. These tiny bones are the smallest bones in the body. The inner ear is composed of the cochlea, which controls hearing, and the vestibular apparatus, which controls balance and equilibrium.
Sound is directed via the external auditory canal to the middle ear. Sound energy is vibrational energy, and when these vibrations reach the tympanic membrane they cause the bones within the ear to vibrate. This vibrational energy is converted to electrical energy within the inner ear. Thousands of tiny hair cells within the cochlea send this electrical energy in the form of nervous impulses along the auditory nerve to the brain. The brain then interprets the meaning of these sounds. Any disruption along this complex pathway can result in a hearing loss.
Are There Different Types of Hearing Losses in Children?
One method of describing hearing losses in children is based on where along the auditory pathway the problem exists. For example, if there is a problem within the external or middle ears, this can result in a conductive hearing loss. The most common causes of hearing problems in children are conductive hearing losses, and the most common cause is otitis media, or inflammation of the middle ear. Otitis media can be caused by viruses, bacteria, or fungi. Otitis media is associated with fluid within the middle ear space. This fluid interferes with sound transmission and results in a temporary hearing loss. Most conductive hearing losses are corrected with either medical or surgical interventions. Other causes of conductive hearing losses in children include excess wax , foreign bodies in the ear canal, or swelling within the ear canal itself.
Hearing loss resulting from a problem in the inner ear is called sensorineural hearing loss. Sensorineural hearing loss is usually permanent and is not routinely corrected with medications. Sensorineural hearing loss can be caused by genetic factors, congenital infections, medications, or prolonged exposure to excessively loud noise (noise-induced hearing loss).
Mixed hearing losses are those hearing losses that have both conductive and sensorineural components. It is necessary to determine the type of hearing loss your child has in order to determine appropriate treatment.
Treatments for Childhood Hearing Loss
Treatment for otitis media and its accompanying hearing loss is important for a child's health and educational success. Studies have shown that such hearing losses can impair a child's ability to listen and learn efficiently.
Treatment options for otitis media have long been controversial. While countries such as Great Britain, adopt a wait-and-see attitude towards treatment, in the United States, otitis media has traditionally been treated with antibiotics. If children have not responded to conventional antibiotic therapy they are sometimes referred for tympanostomy tube placement, or more simply, "tubes." This is an outpatient surgical procedure performed by an ear, nose, and throat surgeon (an otolaryngologist). The goal of placing tubes is to maintain a tiny opening within the eardrum to allow the fluid to drain and prevent its reaccumulation.
Hearing losses can be diagnosed in children who are only minutes old. No child is too young to assess. It is especially important to diagnose and treat sensorineural hearing losses early. Recent studies have demonstrated that children who are diagnosed early, and have the benefit of early intervention, develop speech and language skills similar to their hearing peers. Today, children as young as a few weeks old can be fitted with hearing aids, and even toddlers with profound hearing impairments can benefit from cochlear implants. Cochlear implants are small electronic medical devices used to bypass damage in the cochlea, and reintroduce sound energy to the auditory nerve and brain. They do not cure hearing loss, but they are a feasible, cost-effective alternative for many.
What to Do if You Suspect Your Child Has a Hearing Loss
First off, realize that new innovative treatments exist for childhood hearing loss, and recognize that the earlier the problem receives treatment the better. Parents should take their child to see their primary care physician for initial assessment. Primary care physicians then usually recommend an evaluation by an ear, nose and throat specialist and an audiologist. The audiologist will perform the hearing evaluation. Different types of evaluations are used depending on the age of the child, but children of any age can be assessed for hearing impairments.
Summary
The signs of hearing loss in a child are subtle, yet the consequences of an undetected hearing loss can be devastating. If you suspect that your child might have a hearing problem, obtaining the appropriate diagnosis and treatment early will help to minimize future problems.
Sources for More Information on Childhood Hearing Loss
Alexander Graham Bell Association for the Deaf and Hard of Hearing
2000 M Street, NW
Suite 310
Washington, DC 20036
202-337-5220
http://www.agbell.org
American Academy of Audiology
8201 Greensboro Drive, Suite 300
McLean, VA 22102
800-222-2236
http://www.audiology.org
American Academy of Otolaryngologists and Head and Neck Surgery (AAO-HNS)
One Prince Street
Alexandria, VA 22314
703-519-1589
http://www.entnet.org
American Speech, Hearing and Language Association
10801 Rockville Pike
Rockville, MD 20852-3279
800-638-8255
http://www.asha.org
