Universal Newborn Hearing Screening
Congenital hearing loss is estimated to affect one in every 1,000 newborns. Left undetected, hearing impairments in infants can negatively impact speech and language acquisition, academic achievement, and social and emotional development. If detected, however, these negative impacts can be diminished and even eliminated through early intervention. Because of this, the National Institutes of Health's (NIH) Consensus Development Conference on Early Identification of Hearing Loss (1993) concluded that all infants should be screened for hearing impairment, preferably prior to hospital discharge. Universal newborn hearing screening is a way to identify hearing-impaired newborns with or without risk factors. Newborns with positive screening tests should be referred for definitive testing and intervention services.
First Sound, South Carolina's Early Hearing Detection and Intervention (EHDI) program, functions under a legislative mandate that has been in effect since July 1, 2001. Key team members include South Carolina's hospitals that birth 100+ babies per year, audiologists and the Department of Health and Environmental Control. First Sound staff receives screening results from each screening hospital and tracks each infant that has been referred from ensuring follow up appointments are made with an audiologist through referring to Babynet, the early intervention program if diagnosed with a confirmed hearing loss. First Sound also tracks infants for three years if they pass their hospital screening but are at high risk for developing a late onset or progressive hearing loss.
If your infant failed his or her newborn hearing screening, in depth follow up testing will be scheduled with one of the audiologists and ENT physicians at Greenville ENT. Based on these evaluations, the presence or absence as well the type and amount of hearing loss will be determined. You will then be advised as to whether your infant should use traditional amplification, or if he or she is a cochlear implant candidate.
Speech and Language Development Milestones
The development of communication skills begins in infancy, before the emergence of the first word. Any speech or language problem is likely to have a significant effect on the child's social and academic skills and behavior. The earlier a child's speech and language problems are identified and treated, the less likely it is that problems will persist or get worse. Early speech and language intervention can help children be more successful with reading, writing, schoolwork, and interpersonal relationships.
The course of children's development is mapped using a chart of developmental milestones. These milestones are behaviors that emerge over time, forming the building blocks for growth and continued learning. Your pediatrician will monitor these milestones at regular intervals. Speech and language milestones are listed below:
By age one
Between age one and two
Between age two and three
Between age three and four
Between age four and five
Your child's hearing can be tested at any age. If you or your pediatrician is concerned that any of these milestones are not being met, an evaluation can determined if hearing loss is a contributing factor.
Pediatric Hearing Evaluation
If an infant does not pass the newborn hearing screening, the next phase of testing is diagnostic audiology. An audiologist will perform a series of tests to determine if hearing loss is present, the type of hearing loss, and degree of hearing loss.
A case history will be taken to gather information relating to family history of hearing loss, conditions during pregnancy, labor and delivery, as well as any time spent in the infant intensive care nursery. This information helps the audiologist determine if there are any pre, peri- or postnatal conditions that would indicate the infant is at increased risk for a progressive or late-onset hearing loss.
Auditory Brainstem Response (ABR) testing
ABR testing is a painless electrophysiological test that provides the audiologist with information about the inner ear and auditory nerve. Electrodes are placed on the infant's forehead and earlobes which record neural responses as different auditory stimuli are presented through small insert earphones. The ABR provides information on the degree, type, and configuration of a hearing loss. This information is used to help fit hearing aids and determine cochlear implant candidacy.
Auditory Steady State Response (ASSR)
ASSR is another electrophysiological testing using the same electrodes, which provides more frequency-specific threshold information for infants who have severe to profound hearing losses.
Otoacoustic Emissions (OAE)
A cochlea that is functioning normally not only receives sound, it also produces low-intensity, measurable sounds called OAEs. When greater than mild loss of hearing is present, OAE's are absent. A small soft tip housing a sensitive microphone is placed in the ear canal to measure OAE's.
Include tympanometry and acoustic reflex testing to assess the function of the eardrum and middle ear bones. The mobility of the eardrum can be measured, and the middle ear can be checked for presence of fluid. Acoustic reflexes protect our inner ear from loud noise. The presence of absence of the reflex can help determine the type and severity of hearing loss.
As a child matures and is able to provide hearing results behaviorally, hearing information can be measured with greater specificity. During audiometric testing, the audiologist finds the lowest intensity level (threshold) at which a child can detect sound at different frequencies or pitches. From this information, a graphic representation of the hearing loss, called an audiogram, is created. The hearing loss will typically be classified as mild, moderate, moderately severe, severe, or profound.
For infants 6 - 36 months of age, visual reinforcement audiometry (VRA) is the test method of choice. In VRA assessment, the infant/child is seated on a caregiver's lap in a soundproof booth. The child is trained to turn toward a lighted, movable toy when he/she hears a sound. This method typically results in obtaining a measurement of hearing for the better ear.
An older toddler can be trained for conditioned play audiometry (CPA). In this assessment, the audiologist teaches the child to drop a ball in a bucket or engage in some other fun response activity when he/she hears a tone presented through earphones. This method of testing usually results in an ear specific measurement of hearing.
Amplification with Hearing Aids or Cochlear Implants
If your infant has undergone a complete audiologic assessment by an audiologist and ENT physician, and loss of hearing has been identified, your next steps will include discussion of amplification. If mild to severe loss of hearing has been identified, amplification with traditional hearing aids will most likely be recommended. Hearing aids have a microphone, amplifiers and processors, a receiver, an on/off switch, and a battery compartment. The hearing aid is held in place with a custom made earmold. Sound enters the microphone, is amplified and shaped by the processor, and then directed through the earmold into your child's ear. It is recommended that children identified with loss of hearing via newborn hearing screenings be fit with appropriate hearing aid technology by 6 months of age.
An audiologist will advise you on the use and care of a behind-the-ear style hearing aid designed specifically for pediatric patients. The hearing aid will be programmed based on the tests performed during the audiologic evaluation. Continued testing will be scheduled at regular intervals to ensure that programming is current as more ear specific test data is obtained. As a little ear grows, new earmolds will be made to keep the aids secure.
If severe to profound hearing loss has been identified, consideration will be given to cochlear implantation. The current US Food and Drug Administration criteria for implantation are listed below:
An infant identified with severe to profound loss at less than 12 months of age will be fit with high powered hearing aids to use until they reach surgical age.
A cochlear implant is a surgically placed electronic device that gives sound awareness and speech understanding to persons who cannot make use of even powerful traditional hearing aids.
Cochlear implants have external (outside) parts and internal (surgically implanted) parts that work together to allow the user to perceive sound. The external parts include a microphone, a speech processor, and a transmitter. The microphone picks up sounds-just like a hearing aid microphone does-and sends them to the speech processor.
The speech processor is housed with the microphone and worn behind the ear, like a behind-the-ear hearing aid. The speech processor is a computer that analyzes and digitizes the sound signals and sends them to a transmitter worn on the head just behind the ear. The transmitter sends the coded signals to the implanted receiver just under the skin.
The internal (implanted) parts include a receiver stimulator and electrodes. The receiver is placed under the skin behind the ear. The receiver takes the coded electrical signals from the transmitter and delivers them to the array of electrodes that have been surgically inserted in the cochlea. The electrodes stimulate the fibers of the auditory nerve, and sound sensations are perceived.
As with children using traditional hearing aids, regularly scheduled testing and programming is a requirement to maintain and verify appropriate sound awareness. Audibility of sound is only one aspect of acquiring age appropriate speech and language skills. Hearing aid and cochlear implant wearers must be enrolled in speech therapy and auditory verbal therapy to meet developmental milestones.
Hearing is critical for the development of speech, language, communication skills, and learning. The earlier that hearing loss occurs in a child's life, the more serious is the effect on the child's development. Similarly, the earlier the hearing loss is identified and intervention begun, the more likely it is that the delays in speech and language development will be diminished. Recent research indicates that children identified with hearing loss who begin services before 6 months old develop language (spoken or signed) on a par with their hearing peers.
Cochlear Implant Surgery - What to Expect
Once a child has been determined to be an appropriate candidate for implantation, an MRI and/or CT scan of the temporal bones will be ordered. Imaging studies aid the surgeon in choosing an ear to implant, and reveal any cochlear abnormalities that may affect the placement of the electrode array.
The Centers for Disease Control and Prevention (CDC) issue guidelines recommending the importance of age-appropriate immunizations against specific organisms that cause meningitis in patients who have, or will receive a cochlear implant. The recommendations can be viewed in detail on the CDC website.
The outpatient surgical procedure will be performed under general anesthesia at our main campus on Grove Road. An overnight stay is generally necessary. During the surgery, an incision is made behind the ear to open the mastoid bone leading to the middle ear space. Once the middle ear space is exposed, an opening is made in the cochlea and the implant electrodes are inserted. The electronic device at the base of the electrode array is then placed under the skin behind the ear. The operation is usually completed in 2 to 2 and one half hours.
One week later a post operative visit will be scheduled to inspect the surgical site and remove any remaining dressing. Four weeks after the surgery, the implanted device will be stimulated for the first time. Programming or mapping sessions will be planned at regular intervals. As the patient adjusts to hearing sound, new MAPs will be created to improve sound awareness and discrimination.
If ear infections (otitis media) occur, they should be treated immediately with an oral antibiotic, not an initial period of watchful waiting. If otitis media occurs within 2 months of implantation, intravenous antibiotics may be necessary. Schedule a return visit to Dr. Alexander if your child develops recurrent ear infections in the implanted ear.
If your child develops evidence of acute mastoiditis in the implanted ear, he/she should be seen at GMH urgently as hospital admission will be necessary. Look for signs of fever, irritability, redness and tenderness behind the ear, or drainage from the ear.
After the implant has been turned on, and your child is wearing the external device, monitor the skin in the area of the processor and coil. If your child develop redness, tenderness or swelling at the these sites, discontinue wearing the external device and notify Dr. Alexander's nurse during the week.
The processor and coil should not be worn while sleeping in order to avoid damage to the skin between the magnets that might result in infection and/or skin break down.
If you notice symptoms or have concerns about meningitis, go to nearest emergency room immediately.
If MR (magnetic resonance) imaging evaluation is required, contact Dr. Alexander's office prior to scheduling as magnet removal and subsequent replacement may be necessary.
Follow up with implant audiologist at recommended intervals.
Schedule an office follow up with Dr. Alexander 3 months after surgery.
Aural Habilitation and Speech Therapy
Birth to five years of age is the most important time in a child's life for learning language. Good language skills are necessary to develop the reading and writing skills that are the foundation of education. Identification of hearing loss at an early age, and use of amplification with either hearing aids or cochlear implants is just the beginning. In order to maintain age appropriate speech and language development, aural rehabilitation and speech therapy are imperative for children with hearing loss of any degree.
The early intervention provided through participation in infant and family services can help you understand hearing loss and gain confidence as a parent of a deaf or hard of hearing child. An Early Interventionist (EI) has special training to give babies and young children access to language. Early intervention begins with a visit from an infant/family specialist. She or he is part of a team of professionals, including an audiologist, speech and language therapist, primary care physician, school district representative, an advocate of your choice, and most importantly, you. The primary goal of an Early Interventionist is to help you communicate with your child and encourage his or her development. An EI will work closely with you to identify your needs and set priorities for your baby, help you locate resources, and answer your questions.
In South Carolina, Babynet helps infants and young children identified with hearing loss through the First Steps Program.
Bright Start is a private provider offering EI services in many SC counties.
Another important specialist in the life of a hearing impaired child is a Speech/ Language Pathologist (SLP). An SLP shows a hearing impaired child how to listen and understand when people talk. These skills are necessary to learn new words, understand grammar, and learn to read. SLPs have the specialized preparation, experiences, and opportunities to address communication effectiveness, communication disorders, differences, and delays due to a variety of factors including those that may be related to hearing loss.
Children with hearing loss need training to learn to listen well while using a hearing aid or hearing assistive device. One of the first things they learn is to be aware of the sound of their parent's voice and other interesting things in their home environment. Very quickly, they learn that sounds have meaning. As they get older, they will be taught to “discriminate” between different sounds of speech (e.g., “b” sounds different than “th”). Adults who gradually lose their hearing over time already understand language and have speech. Infants and young children have not yet learned these skills. In young children with hearing loss, speech and language development can be delayed. Speech-language pathologists work with families to help their children with hearing loss develop language understanding (reception) and language use (expression).
Auditory-Verbal Therapy (AVT) is an effective form of therapy for children with hearing impairment to learn to recognize, understand and speak words. This therapy is based on auditory (listening) and verbal (speaking) communication skills development. Children with hearing loss need help learning to detect and recognize sound around them with the assistance of their hearing aids or cochlear implants. AVT encourages maximum use of hearing by stressing listening rather than watching. Resources for more information can be found at Listening For Life and The AG Bell Academy for Listening and Spoken Language.