Service provision for children with permanent childhood hearing loss begins soon after the diagnosis is made and comprises audiologic re/habilitation-including the selection, fitting, and evaluation of technology (if amplification is selected as the treatment approach)-and a family-centered and interdisciplinary comprehensive early intervention program.
When selecting any treatment approach, the audiologist considers and incorporates the family's goals, preferences, values, beliefs, culture, and linguistic background.
Attempts should be made to fit hearing aids within 1 month of diagnosis. Loaner hearing aids can be provided until financing is secured, to avoid a delay in fitting.
Candidates for amplification include children with any degree of hearing loss that has the potential to impede access to speech. Candidates include children with
- permanent bilateral hearing loss,
- chronic hearing loss due to otitis media,
- unilateral hearing loss,
- auditory neuropathy (trial amplification based on behavioral results and observations).
In addition, cochlear implant candidates often have a trial amplification period.
- Behind-the-ear (BTE) is the most commonly recommended type of device for infants and young children, because the softer, safer earmold materials are not easily cracked and broken. Earmolds will need frequent replacement to account for rapid ear growth through age 7 or 8 years.
- Binaural amplification is to be provided to young children with bilateral hearing loss unless there is a clear contraindication (The Pediatric Working Group of the Conference on Amplification for Children With Auditory Deficits, 1996).
- Connectivity to a wide range of HATs may be provided through direct audio input (DAI), built-in FM receiver, or telecoil.
- Device selection considerations include the presence of flexible electroacoustic characteristics to accommodate changes in hearing over time; multiple memories to allow caregivers to adjust the hearing aid for different listening conditions; data-logging capability to monitor hearing aid use; volume control and memory button disable options; safety-related features, such as tamper-resistant battery doors; cosmetic considerations, such as earmold and/or hearing aid color; and the inclusion of a parent/caregiver kit.
Selection of Advanced Hearing Aid Features
Children with hearing loss may benefit from the provision of specific advanced signal-processing features in hearing aids, such as digital noise reduction, directional microphones, and frequency lowering strategies. Decisions about the activation or selection of these features, however, are typically based on available peer-reviewed evidence, as well as the age and listening needs of the child. Whereas some technologies have been investigated in older children, studies in this birth-to-5 years of age population have not been conducted at this time.
The audiologist obtains probe microphone measures of real-ear performance from the child whenever possible. Aided functional gain measured in a sound field for the purpose of setting devices is not sufficient and may result in less than optimal hearing aid fittings (Humes & Kirn, 1990).
The primary goals of probe microphone measures for verifying a hearing aid fitting are to
- optimize the audibility of speech across frequencies,
- protect the child from loudness discomfort or potential damage to hearing from amplified sound,
- provide quick, repeatable, and valid measures of "goodness of fit."
A prescriptive approach is essential. For infants, the most appropriate prescriptive approach is one that is audibility based and accounts for the physical differences between children and adults. The
DSL [v5] and
NAL-NL2 (National Acoustics Laboratories) fitting procedures can provide this information.
Sound pressure levels and ear canal resonance measured in young ears typically exceeds adult values due to the smaller residual volume between the earmold and tympanic membrane. The real-ear-to-coupler difference (RECD) is the difference between the acoustics measured in the 2cc coupler and the acoustics measured in the child's own ear with the earmold inserted. The hearing aid, using the infant's own earmold, can easily be set in the test box using the RECD combination with test-box measures to predict real-ear responses (The Pediatric Working Group of the Conference on Amplification for Children With Auditory Deficits, 1996).
RECD measurements are completed
- during or after first fit,
- during monitoring visits,
- with all new earmold fittings.
The audiologist verifies hearing aid settings in the child's ear (when possible) or simulated test-box measures for soft, average, and loud speech stimuli and for maximum output limits.
Validation of the aided auditory function is a critical component of the pediatric amplification-fitting process. The purpose of validating aided auditory function is to demonstrate the benefits and a limitation of a child's aided-listening abilities for perceiving the speech.
In the audiology clinic, hearing aids are often validated using developmentally and linguistically appropriate speech-perception materials in an aided sound-field condition. Speech stimuli, such as the
Ling sounds, can be used for functional assessment of the audibility of speech sounds in the clinic or in other settings. Hearing aids are validated in the home/daycare or school setting by parents/teachers/ early intervention providers using questionnaires that measure functional auditory performance based on age.
Counseling and Orientation
Typically, all family members and any professionals who will be working with the child receive hearing aid orientation. Printed handouts in easy-to-understand language are provided to supplement the orientation, because many parents will not remember all of the information presented (Eiser, Parkyn, Havermans, & McNinch, 1994; Reese & Hnath-Chisolm, 2005).
Counseling and orientation typically include information regarding
- care, maintenance, and troubleshooting, such as
- cleaning and storage,
- listening check with a stethoscope,
- battery checks,
- acoustic feedback;
- safety features and issues, such as
- battery ingestion and tamper-proof battery doors,
- appropriate ear placement (left versus right);
- realistic expectations, such as
- effects of degree and configuration of hearing loss,
- effects of background noise and distance,
- environmental awareness;
- importance of routine hearing aid usage.
Fitting personal amplification in an infant or young child is an ongoing process. At a minimum, an audiologist typically sees a child every 3 months during the first 2 years of using amplification and every 4 to 6 months thereafter, with more frequent visits if there are concerns. Children with fluctuating or progressive hearing loss may need more frequent monitoring. Earmolds may need to be replaced every 3 to 4 weeks during the first year of the child's life (The Pediatric Working Group of the Conference on Amplification for Children With Auditory Deficits, 1996).
Follow-up appointments include
- audiologic evaluation to monitor hearing status,
- periodic assessment of functional measures to document auditory skills,
- electroacoustic evaluation and listening checks of the hearing aids,
- re-evaluation of the RECD and other probe-microphone measures as appropriate. RECD are typically re-measured whenever earmolds are replaced.
Note: The section is an overview. A Practice Portal page on cochlear implants will be developed in the future.
Cochlear implant candidacy criteria have evolved over time with advances in cochlear implant technology and subsequent improvements in performance outcomes. Guidelines for cochlear implant candidacy are given with the FDA approval of each system and are based on the participant criteria used for the clinical investigation of the system's safety and efficacy. These guidelines have also changed substantially over time. As cochlear implant devices continue to improve, the criteria regarding the degree of hearing loss and the performance with a hearing aid that warrants consideration of a cochlear implant will continue to evolve.
Determining candidacy for cochlear implants requires an evaluation of the patient's medical, audiological, and psychosocial/habilitative condition using a team approach. Candidacy factors include:
- bilateral severe-to-profound sensorineural hearing loss;
- auditory neuropathy/dyssynchrony;
- an age of 1 year or older (exceptions dependent on etiology);
- a history of limited or no benefit from binaural hearing aids coupled with intensive auditory training;
- an absence of medical contraindications, such as chronic middle ear pathology, some lesions of the VIIIth cranial nerve, some pathologies of the central auditory pathway, and other medical issues that preclude surgical procedures;
- a family commitment to post-implant appointments and the re/habilitation process and realistic expectations for cochlear implant use and benefit.
- audiologic evaluation including hearing aid evaluation,
- medical evaluation/radiologic studies,
- vestibular evaluation,
- psychosocial and/or psychological evaluation,
- speech-language evaluation,
- discussion of family expectations.
There are three manufacturers of cochlear implants in the United States: Cochlear Ltd., Advanced Bionics Corporation, and MED-EL. The selection of the device depends on a number of factors, including
- U.S. Food and Drug Administration (FDA) indications for the device,
- surgeon and audiologist recommendation,
- family preference,
- availability of devices at the cochlear implant center the family selects.
Research continues to assess the efficacy of bilateral cochlear implantation, which can be be performed simultaneously or sequentially. Advantages to bilateral cochlear implants are better sound localization and significantly improved speech recognition performance in the presence of background noise (Litovsky, Johnstone, & Godar, 2006).
Device activation occurs 2 to 6 weeks after implantation of the internal device. At the beginning of each appointment, the components on the external sound processor are inspected, and the impedances of each electrode are checked through telemetry to ensure adequate current flow.
The speech processor is programmed using objective or behavioral measures to provide sufficient stimulation of the internal electrodes so that speech and other auditory stimuli are audible, comfortable, and below a threshold of discomfort. An effort is typically made to restore normal loudness percepts.
Objective measures for mapping include the electrically evoked stapedius reflex threshold (ESRT) conducted with standard immittance equipment and the electrically evoked compound action potential (ECAP) available through the programming software. These measures are noninvasive and do not require a response from the patient.
Behavioral measures for mapping, such as BOA, VRA, and CPA, can be employed for children who are able to give reliable responses. These techniques are often paired with objective measures to ensure an appropriate map. Additionally, sound-field testing assists in verifying the appropriateness of the map for functional detection of sound.
Validation is a critical component of the cochlear implant (CI) programming process. The purpose of validating auditory function is to demonstrate the benefits and limitations of a child's listening abilities for perception of speech and other auditory stimuli.
Cochlear implant function is validated through speech perception, progress in speech-language therapy, and via questionnaires. Audiologists use developmentally and linguistically appropriate speech-perception materials in an aided sound-field condition to assess a hierarchy of listening skills that range from detection through comprehension of a spoken message. Proper function of the CI is also validated by the child's speech-language pathologist through achievement of age-appropriate goals and objectives. Validation is typically also accomplished in the home, daycare, or school setting using questionnaires that measure functional auditory performance in everyday listening environments.
All family members and any professionals who will be working with the child typically receive orientation to the cochlear implant. Counseling and orientation include routine troubleshooting and realistic expectations for the child's performance.
Children return often for programming during the first year (e.g., 2, 4, 8, and 12 weeks, 6 months, 12 months). During this time, the programming parameters are refined. During these appointments, children are taught to provide feedback on soft, comfortable, and loud sounds.
Follow-up appointments include
- impedance and equipment check,
- updated programs,
- behavioral assessment, including threshold and speech perception tests,
- feedback from parents and providers regarding functional listening skills in the home or daycare environment,
- discussion regarding progress made in auditory and communication development.
In many situations, distance, background noise, and reverberation effects can interfere with optimal audibility. HATs can help a listener overcome the negative consequences of these variables. Remote microphone technology HATs overcome the effects of noise, distance, and reverberation by placing a microphone close to a talker's mouth or sound source. Thus, they can improve communication access for children in adverse listening environments.
While many remote microphone HAT options exist, the focus of this discussion is personal FM (frequency-modulated) systems. Personal FM systems consist of two parts: a wireless transmitter and a small wireless receiver. The transmitter sends a low power FM radio signal. This signal is picked up by the receiver, which may be connected to a hearing aid or cochlear implant processor or worn as an ear level FM-only receiver.
Children with any degree or type of hearing loss- including current or potential hearing aid and cochlear implant users-may be considered candidates for personal FM use.
Consideration factors for the selection of FM technology for this age include
- the degree and configuration of the child's hearing loss, his or her current use of hearing technology, chronological and developmental age, and listening environments (home, daycare, car, school, etc.);
- concerns, such as attention, hyperactivity, sensory integration, behavior, cognition, mobility, auditory processing, learning, vision, and fine motor issues;
- technology issues (convenience, wearability, reliability, maintenance, compatibility with existing amplification, etc.);
- parental/child/caregiver/educational motivation and ability to use the device and financial resources.
It is necessary for the audiologist to conduct verification of the performance of the FM system when fitting a child. Specific procedures vary based on the unique characteristics of the listener and the device configuration, but typically include one or more of the following
- electroacoustic analysis,
- real-ear probe microphone measures,
- behavioral measures, such as sound-field aided speech recognition.
Validation is an ongoing process whose purpose is to demonstrate the benefits and limitations of a child's listening abilities for perception of speech. Objective validation for FM systems is typically conducted with developmentally appropriate speech-perception materials in conditions that reflect the typical listening environment of the listener. Subjective validation may also be completed using observation questionnaires completed by parents/teachers/caregivers. In addition, IDEA requires that use of assistive technology include a functional evaluation of the listener in his or her customary environment (Federal Register, 2006).
Daily checks of the FM system are typically performed by the parent, teacher, speech-language pathologist, or anyone who has received appropriate training by the audiologist. A daily check consists of visual inspection of the device and its coupling, followed by listening to the sound quality. If possible, the listening check is performed in the room(s) where the FM system is used so that interference will be detected.
The audiologist's periodic comprehensive monitoring of the FM system may include electroacoustic analysis, probe microphone measurements, and other in-depth troubleshooting measures. Typically, these comprehensive procedures are performed at least annually and more frequently if there is a change in hearing status and/or hearing technology or an unresolved problem is identified during the daily check.
Periodic evaluations of a child's hearing status and performance with the FM device are necessary to monitor stability of hearing, appropriate device settings, and degree of benefit with the FM. These assessments may include, but are not limited to, audiologic evaluations, real-ear probe microphone measurements, behavioral assessment of speech recognition, and observations of performance in normal-use settings.
Osseointegrated devices (e.g., bone-anchored hearing aids) are considered for children with permanent bilateral conductive or mixed hearing loss or single-sided deafness. The FDA has not approved surgical implantation of bone-anchored hearing aids for children less than 5 years of age; however, children under 5 can wear the external processor in a soft band until they are old enough for implantation. There are currently two manufacturers for osseointegrated devices in the United States: Cochlear Corporation and Oticon.
Auditory Brainstem Implants (ABI)
Auditory brainstem implants (ABI) provide electrical stimulation of the cochlear nucleus in the brainstem for patients who do not have a cochlea or auditory nerve. Clinical trials are currently in process and include children who are not candidates for cochlear implantation. Research is needed to better describe the candidacy requirements and long-term outcomes for communication development with ABIs.
Audiologists' and speech-language pathologists' roles in the provision of pediatric audiologic re/habilitation services may be complementary, interrelated, and, at times, overlapping. It is important to understand that both professions also have distinct areas that are defined by their respective scopes of practice, certification standards, and preferred practice patterns. For example, audiologists are uniquely qualified to perform diagnostic assessment of hearing and to verify and validate hearing aids, cochlear implants, and other technology. Speech-language pathologists are uniquely qualified to perform diagnostic evaluations of communication, speech, language, cognition, and swallowing. Audiologists, however, may screen for speech, language, and communication skills and/or provide aural re/habilitation therapy.
Activities in which both audiologists and SLPs engage include
- evaluating of functional communication performance;
- conducting auditory perception training-including activities to improve sound awareness, discrimination, recognition, and comprehension;
- managing and encouraging consistent use of devices;
- counseling parents/caregivers regarding modes/methods of communication;
- determinating optimal training and education settings;
- monitoring acoustics of home, daycare, and school settings and providing recommendations for modifications;
- counseling the child with hearing impairment and his or her family regarding peer pressure, stigma, and other issues related to psychosocial adjustment;
- counseling the child and family regarding behavioral coping strategies;
- monitoring treatment benefit and outcome;
- collaborating effectively as part of multidisciplinary teams and communicating relevant information to allied professionals and other appropriate individuals;
- planning and implementing parent-education programs concerning the management of hearing impairment and subsequent communication difficulties;
- referring individuals to parent-to-parent support and other consumer-based organizations.
Children under age 3 are referred to both the state
Early Hearing Detection and Intervention (EHDI) and
Infant and Toddlers Early Intervention (Part C) programs as soon as they have been diagnosed with hearing loss. Children over 3 years of age are referred to their respective local area school systems' special education programs (Part B). Both Part C and Part B of IDEA are federally funded grant programs that assist states in developing, and in many instances funding, comprehensive services for children with disabilities, including hearing loss.
Specific services for children vary state by state and will depend on the individual needs of the child as dictated by the
- current age of the child,
- age that hearing loss started,
- age at which hearing loss was diagnosed,
- age at which hearing aids or cochlear implants were introduced,
- age at which therapy and intervention services were started,
- severity of hearing loss,
- type of hearing loss,
- comorbid conditions,
- family desires and goals for their child.
Audiologists treat children who use a variety of communication methods, including listening and spoken language, cued speech or cued language, sign language, simultaneous communication, and total communication, often working collaboratively with SLPs, teachers of the deaf, and other professionals to provide services.