February 13, 2007 Features

Babies with Hearing Loss: Steps for Effective Intervention

Improved and more widespread screening programs identify more infants with hearing loss at an increasingly younger age. Helping families find and access appropriate early intervention services for their infants is a critical follow-up to these crucial evaluations.

Until the 1990s, children born with a significant hearing loss typically would not have been identified until 2 ½ to 3 years of age. But with the new universal programs that screen newborns for hearing loss, more children with congenital hearing loss are being identified at birth. Better coordinated and responsive follow-up systems also ensure earlier detection and treatment.

Auditory brainstem response (ABR) and otoacoustic emissions (OAE) screening techniques paved the way for quick, effective ways to screen the hearing of babies. The Rhode Island Hearing Assessment Project concluded that newborn hearing screening was both feasible and economically practical. Funded in 1989, the project was sponsored by the U.S. Health Resources Services Administration and the U.S. Office of Special Education and Rehabilitative Services.

In 1990, Hawaii was the first state to establish newborn hearing screening. Ten years later, 32 other states had passed newborn hearing screening legislation. All 50 states, the District of Columbia, and two territories now have Early Hearing Detection Intervention (EHDI) programs.

Healthy People 2000, a national health promotion and disease prevention initiative, sought an average age of 12 months for identification of congenital hearing loss. A decade later, Healthy People 2010 includes additional benchmarks: hearing screenings by one month, audiologic evaluation by three months, and early intervention by six months of age.

A Medical Home

For young children with congenital hearing loss, newborn hearing screening is the first step. The child's primary health care provider, in partnership with the parent(s), seeks to identify and meet the medical and non- medical needs of the child and family. This comprehensive approach, known as the "medical home," coordinates the audiologic evaluations and management, medical specialty evaluations, and early intervention services.

Follow-up services are crucial for babies whose initial screening indicates hearing loss. But many factors delay follow-up: families and primary care providers who do not confirm a newborn's hearing status after a failed screening; incomplete data or inadequate data systems for tracking and surveillance; and lack of appropriate services for infants identified with hearing loss, especially mild hearing loss.

Efforts to study and improve the rate of follow-up are underway in eight states through a learning collaborative of the National Initiative for Children's Healthcare Quality (NICHQ, www.nichq.org), a national organization dedicated to improving the quality of health care provided to children. NICHQ focuses on all components of the EHDI system (see sidebar) and identifies strategies to help move babies through the process in a timely manner.

However, one of the primary challenges for the EHDI system is the shortage of audiologists who are skilled in working with infants and very young children. As the EHDI system has grown, demand has increased for audiologists with the expertise to provide diagnostic, habilitation, counseling, and coordination services.

After identification of permanent hearing loss, referrals typically go to otolaryngology, genetics, ophthalmology, and early intervention services. Parents should be offered contacts for parent-to-parent support, an often-identified request of parents who have just discovered that their child has hearing loss.

Amplification Provision

If amplification is indicated for a baby with hearing loss, early, appropriate amplification requires accurate estimates of hearing sensitivity. For infants, a typical audiological test battery consists of ABR, high-frequency tympanometry, and OAEs, with behavioral audiometric testing when developmentally feasible. Data about threshold agreement between tone burst ABR and behavioral audiometric tests for children have been published, supporting the use of both tools.

Auditory steady-state response (ASSR) applications for infants and young children with hearing loss are continuing. However, some recent publications suggest that ASSR should be used cautiously with infants.

Delays to fitting amplification may be due to problems with scheduling, the need for repeat tests, suspicion of auditory neuropathy/dys-synchrony, and the cost of hearing aids (Harrison, et al, 2003). Delays in fittings also are likely for babies who are medically fragile or very premature.

The amplification process can be thought of as a five-step approach:

1. Selection
2. Verification
3. Orientation
4. Validation
5. Follow-up

Selection Options

The selection stage begins the process of the infant's communication skill development. The family helps choose earmolds and hearing instruments; options are restricted by the relatively small size of infants' ears. The small sound bore limits earmold modifications that might otherwise enhance high-frequency amplification. The earmold material should be a soft material, typically silicone or vinyl.

Typically recommended pediatric hearing aids are binaural behind-the-ear and FM-compatible with flexible electroacoustic characteristics. Tamper-resistant features are necessary.

Acoustic feedback occurs often for babies, as they quickly outgrow earmolds. As a stopgap measure, lubricants can extend earmold use. Many hearing aids have feedback reduction circuitry—but verifying reduction is critical to assure uncompromised audibility.

Evidence for the specific circuitry to be used with infants is scant. Wide dynamic range compression (WDRC) hearing aids are appropriate for children who have mild to moderately severe hearing loss, according to a review of the literature by Palmer and Grimes (2005). They state that evidence supports the use of low compression thresholds, moderate compression ratios, and fast attack times.

A pediatric-specific prescriptive approach to ensure audibility of typical speech-level inputs guides electroacoustic targets for gain and output. The Desired Sensation Level (DSL) approach, developed by Seewald and colleagues, provides such targets. Three recent DSL articles in Trends in Amplification (2006) provide a historical perspective, as well as an update of the latest DSL version. These articles are a must-read for pediatric audiologists.

Verification

Verification, which can be behavioral or electroacoustic, focuses on whether speech audibility is met for a wide range of inputs audible. For infants, electroacoustic verification is the only feasible option. It provides frequency-specific information about the audibility for a wide variety of speech inputs, as well as estimates of the real-ear saturation response (RESR).

Because infants are unlikely to tolerate repeated probe-microphone measures, electroacoustic verification for them includes real-ear-to-coupler- difference (RECD) measures combined with coupler values to predict the real-ear aided response (REAR) and RESR. Predicted responses based on manufacturers' simulations of hearing instrument performance do not always predict real-ear performance.

Orientation

To promote consistent hearing aid use, parents and/or caregivers need information about proper care, appearance, and benefits of the devices (Sjoblad, et al., 2001). Because every family is unique, it is important that the audiologist ask each parent about concerns at initial and follow-up sessions.

Demonstrations should include how to take care of the earmolds and hearing aids; insert the earmolds and put the hearing aids in place; and remove the devices. Practice and repetition are necessary, as with any new skill. Daily listening checks are vital because infants cannot tell anyone when a hearing aid is malfunctioning. The family must be supplied with hearing aid maintenance tools: batteries, earmold blower, drying system, listening tube/stethoscope, earmold lubricants, retention device, battery tester, and wax loops. All orientation information should be provided in written form.

Child-friendly retention devices, including pediatric tone hooks, help babies accept and retain the devices. Many manufacturers have pediatric hearing instrument care kits.

Validation Measures

To validate the benefit of hearing aids, older children and adults complete speech perception measures while wearing the device. Babies require other validation measures, which often are subjective and depend on parent reports or clinician observations. Examples of subjective measures include the Early Listening Function (ELF), the Functional Auditory Performance Indicators (FAPI), and the Infant-Toddler Meaningful Auditory Integration (IT-MAIS).

The ultimate validation measure is speech and language development. In the early months of life, babbling and phoneme development should be monitored carefully. The partnership between parents, teachers, therapists, and audiologist is important to determine if changes in amplification are needed.

Follow-up

Following the identification and confirmation of hearing loss, and the hearing aid fitting, a reasonable follow-up schedule for children less than 2 years old is every three months. At that time hearing is monitored, hearing aids are tested and adjusted, and new earmolds are made when needed. Semiannual visits are appropriate for most children from 2 to 6 years of age, with annual follow-up thereafter, unless hearing-loss progression risk factors are present.

Jeff Hoffman, is the program manager for the Nebraska Newborn Hearing Screening Program and is a member of its Advisory Committee. He has also worked in elementary education, counseling and family services, administration of early childhood programs, and Head Start training and technical assistance services. Contact him at jeffkhoffman@yahoo.com.

Kathy Beauchaine, is an audiology coordinator at Boys Town National Research Hospital. She was a member of the ASHA committees that developed the Audiology Screening Guidelines; the Audiological Assessment Guidelines for 0-5 years; and the Roles, Knowledge and Skills for Pediatric Audiological Assessment. Contact her at beaucha@boystown.org.

cite as: Hoffman, J.  & Beauchaine, K. (2007, February 13). Babies with Hearing Loss: Steps for Effective Intervention. The ASHA Leader.

Early Hearing Detection Intervention

The concept of a comprehensive Early Hearing Detection Intervention (EHDI) system is supported by two national organizations: the Joint Committee on Infant Hearing (Year 2000 Position Statement) and the Centers for Disease Control and Prevention (National Goals, Objectives and Performance Indicators for the EHDI Tracking and Surveillance System). Key elements of the two documents include:

  • Screening of all newborns using a physiologic measure of hearing during birth admission.
  • Audiologic evaluations for those who do not pass the screening by 3 months of age.
  • Appropriate, interdisciplinary early intervention services prior to 6 months of age for all infants identified with permanent hearing loss.
  • Monitoring for infants with hearing loss risk factors to identify late-onset, progressive, or acquired hearing loss.
  • Protection of the rights of infants and their families through informed choice, decision-making, and consent.
  • Protection of screening and evaluation results, similar to other health and educational information. 
  • A medical home for infants with permanent hearing loss.
  • Tracking and surveillance information systems that measure and report the effectiveness of EHDI services and minimize loss to follow-up.
  • Comprehensive data systems that monitor quality, track progress toward goals, and determine compliance and accountability.  


Percentage of Newborns Screened

State laws vary in their requirements for the number of newborns who must be screened. Reporting, health insurance coverage, and written informed consent requirements also vary. In 2004, more than 91% of newborns nationwide were screened, most prior to discharge from birth admission, compared with 3% as recently as 1993. Almost 2% of the newborns screened for hearing loss were referred for an audiologic evaluation; of those who did receive an audiologic evaluation, 75% were evaluated prior to 3 months of age. However, only 48% received the recommended audiologic evaluation; the remaining 52% were "lost to the system."

Amplification Guidelines

Amplification for infants and children is guided by national practice standards/guidelines and peer-reviewed literature. The Pediatric Working Group (ASHA, March 1996, Amplification for Infants and Children With Hearing Loss, American Journal of Audiology; 5:53-68) document remains an excellent resource for audiologists, detailing the primary considerations for and decisions involved in fitting amplification to children. Other key documents are: Guidelines for Audiometric Assessment of Children (ASHA, 2004); Roles, Knowledge and Skills for Audiometric Assessment of Children (ASHA, 2006); Pediatric Amplification Guidelines (AAA, 2004); and Genetic Evaluation Guidelines for Etiologic Diagnosis of Congenital Hearing Loss (American College of Medical Genetics, 2002). The Joint Committee on Infant Hearing position statement revision is almost completed and likely will include new recommendations for audiological care/follow-up.

Resources

Three suggested Web sites for parents are:

My Baby's Hearing (Spanish-language version), Listen Up and Alexander Graham Bell Association for the Deaf and Hard of Hearing. Each has a slightly different focus on children with hearing loss, and all have extensive links to other resources.

Related Web sites for audiologists, in addition to the ASHA Web site resources, are:

Maternal and Child Health Bureau, Universal Newborn Hearing Screening

Centers for Disease Control and Prevention, Early Hearing Detection and Intervention

National Institute on Deafness and Other Communication Disorders

National Center for Hearing Assessment and Management

Joint Committee on Infant Hearing

American Speech-Language-Hearing Association Technical Assistance, Healthy People 2010–Health Objectives for the Nation and Roles of Audiologists and Hearing Scientists [PDF]



References

American Academy of Audiology. (2003, October). Pediatric Amplification Guidelines. Available from www.audiology.org.

American Speech-Language-Hearing Association. (2006). Roles, knowledge, and skills: Audiologists providing clinical services to infants and young children birth to 5 years of age.

American Speech-Language-Hearing Association. (2004). Guidelines for the audiologic assessment of children from birth to 5 years of age.

Bagatto, M. et al. (2005). Clinical protocols for hearing instrument fitting in the desired sensation level method. Trends Amplification, 9, 199-226.

DSHPSHWA data summary: Reporting year 2004. Available from http://www.cdc.gov/ncbddd/ehdi/2004/Data_Summary_04D_web.pdf [PDF]

Joint Committee on Infant Hearing. (2000). Year 2000 position statement: Principles and guidelines for early hearing detection and intervention programs. Pediatrics, 106, p. 798-816.

National Goals, Objectives and Performance Indicators for the EHDI Tracking and Surveillance System. Available from www.cdc.gov/ncbddd/ehdi/nationalgoals.htm

Nemes, J. (2006). Success of infant screening creates urgent need for better follow-up. The Hearing Journal, 59,21-28.

Pediatric Working Group. (1996). Amplification for infants and children with hearing loss. American Journal of Audiology, 5(1), 53-68.

Seewald, R., Moodie, S., Scollie, S. and Bagatto, M. (2005). The DSL method for pediatric hearing instrument fitting: Historical perspective and current Issues. Trends in Amplification, 9, 145-157.

Scollie, S., et al. (2005). The desired sensation level multistage input/output algorithm. Trends in Amplification, 9, 159-197.

White, K. (2003). The current status of EHDI programs in the United States. Mental Retardation and Developmental Disabilities Research Reviews, 9, 79-88.



  

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