Testing a child's hearing can be very different from testing an adult. At Brenner Children's, we have a dedicated pediatric audiology clinic where children receive the unique care they require.
Months before a child can respond to sound, we can use objective tests to estimate and better understand hearing, starting with the newborn hearing screening.
For toddlers and children:
As a child develops the ability to respond consistently to sound, we use enjoyable activities to determine the softest sounds a child can hear. We may use visual reinforcement audiometry, so that children are taught to turn to a toy when hearing a sound, or conditioned play audiometry, so that children are taught to perform a task when hearing a sound (like putting a block in a bucket). If amplification is required, we work with both the child and the family to ensure that the child has every opportunity to maximize his or her hearing potential.
For school age children:
We provide tests of auditory processing abilities to examine how a child is processing what is heard and make recommendations accordingly.
Behavioral Hearing Tests for Children
Our audiologists conduct behavioral hearing tests to observe a child's behavioral response to sounds. These responses may include head turns, eye movement, raising a hand, or doing a simple activity, depending on the age of the child. One or a combination of tests may be used and will be customized for each patient.
Conventional Test Techniques
These techniques are used with older children. A speech reception threshold (SRT) is obtained by asking patients to repeat familiar bisyllabic words (e.g. baseball) at gradually decreasing intensity (loudness) levels, until the level of the softest words that can be repeated is identified. Then, pure tone audiometry begins. Patients are asked to push a button or raise their hand when a tone is heard. A pure tone audiogram is generated, which is a graph indicating thresholds at the various frequencies or pitches tested, from low to high.
Visual Reinforcement Audiometry
This procedure is typically used for children in the 6 month to 2 1/2 year age range. With this technique, young children are taught to turn toward an animated toy every time they hear a sound. Since small children cannot repeat words, a speech awareness threshold (SAT) is determined by gradually decreasing intensity (loudness) levels of a speech signal, until the softest speech to which the child turns is identified. Then, an audiogram is generated by observing the head turn response for certain pitches or sounds.
Conditioned Play Audiometry
This test is frequently done for children in the 2 to 5 year range. Children are taught to perform a simple task (e.g. putting rings on a peg) every time they hear a sound. The goal is to obtain the same information as obtained with conventional test techniques described above, but in a more motivating manner that holds the attention of small children.
Speech Recognition Tests
When hearing loss is present, it is important to determine how well the patient can understand speech. A variety of speech recognition tests are available for patients ranging from 3 years through adulthood. During these tests, the audiologist asks the child to repeat target words.
Auditory Brainstem Response Hearing Tests
Auditory Brainstem Response (ABR) testing, also known as auditory evoked potential testing, allows us to estimate hearing levels based on neurological activity in the auditory system. Sounds are introduced through earphones while electrodes area placed on the child's head to measure brainstem electrical activity. ABR is a pain-free test but requires that the patient be very still or asleep. Sedated testing is available if necessary.
Newborn Hearing Screening
Our audiologists manage newborn hearing screening at Brenner Children's. Newborn hearing screening is required for all infants born in North Carolina. Full term babies can be tested in the first 24 to 48 hours of life, and premature infants should be at least 34 weeks post-conception before testing.
Newborns undergo hearing screening using an automated form of the ABR test called Automated Auditory Brainstem Response testing. The test is quick and pain free. Electrodes are placed on the baby's forehead and behind the ears to record neural responses to sound. It is important that the baby sleep during this test.
If a baby fails the screening, the test is repeated once. Possible reasons may include having debris in the ear canal, middle ear fluid, or more permanent hearing loss. If the baby fails again, we perform diagnostic testing.
Diagnostic ABR Test
Diagnostic ABR testing is performed when an infant fails to pass the newborn hearing screening after at least two attempts. Diagnostic ABR testing can also be performed on children when hearing cannot be reliably evaluated with routine behavioral test methods or other objective tests. ABR testing is available using both clicks and tone bursts to estimate hearing at different frequencies. The hearing levels and ABR response characteristics can help establish the degree and type of hearing loss, and if medical management or hearing aids are needed.
Middle Ear Hearing Testing for Children
These tests are used to check middle ear function - a common cause of hearing loss. Problems such as fluid in the middle ear, a hole in the eardrum, or problems with the small bones in the middle ear can result in conductive hearing loss that generally can be treated medically or surgically. To obtain a tympanogram (to test middle ear function), a small earphone is placed in the ear canal, and eardrum movement is measured in response to small changes in air pressure. The acoustic reflex test checks the function of a small muscle in the middle ear.
Otoacoustic Emissions (OAE) Test
This test can be used to determine if the tiny hair cells in the inner ear are functioning normally. The procedure is painless and can be performed at any age, even in newborns. To measure OAEs, a miniature earphone and microphone are placed in the ear canal. Sounds are presented and a response or "emission" from the inner ear is recorded. Patients do not need to respond in any way; they simply need to remain quiet for a few minutes. When testing young children, toys and other visual distractions are used to keep them quiet and calm. The test can be performed while the child is asleep.
Central Auditory Processing Assessment
Central auditory processing is how your brain responds to what your ears hear. Children who have difficulty with auditory processing usually have normal hearing, but have difficulty in certain situations:
- They may understand speech in quiet, but have trouble understanding speech clearly if there is background noise.
- They may have difficulty with short-term auditory memory and cannot remember something heard, such as a verbal series of instructions
- They cannot process information quickly and can understand better if the speaker slows down and speaks in shorter sentences
Evaluating Central Auditory Processing Disorder
We can perform central auditory processing evaluations on children age 6 and over. The appointment lasts approximately 2 hours, and the audiologist gives parents test results and suggestions for exercise that might be helpful in the classroom.
If a central auditory processing disorder is diagnosed, we usually refer the child for further testing to a speech-language pathologist, who determines if remedial therapy is recommended. We have speech-language pathologists at Brenner Children's, or sometimes therapy can be performed by the child's school speech therapist.
The testing is designed for children with low to average cognitive abilities, so if another disability (such as overall cognitive delay) is suspected, it should be evaluated first. Children can have a central auditory processing disorder in combination with other disabilities, such as a learning disability or Attention Deficit Disorder (ADD or ADHD). If a child is diagnosed with ADHD and takes medication, we want the child to be on the medication for the testing.