Hearing Test Protocols for Children
Key Points
- Pediatric audiologic assessments involve the detection of developmentally appropriate protocols that include the cross-check principle
- Before testing, the child's cognitive age and physical status must be determined
- A case history contributes valuable diagnostic information, provides an opportunity to observe the child, and allows a rapport to be established between the audiologist and family
- Functional auditory assessments, in the form of paper-and-pencil surveys, can assist in monitoring the baby's or child's auditory progress over time
The Cross-Check Principle for Test Batteries
- There are four main purposes for a pediatric audiologic assessment
- obtain a measure of peripheral hearing sensitivity that rules out or confirms hearing loss as a cause of the baby's or child's problem
- to confirm the status of the baby's or child's middle ear
- to assess auditory functioning using speech perception measures when possible
- to observe and interpret the baby's or child's auditory behaviors
- "Cross-check" principle is standard
- several appropriate behavioral and electrophysiologic tests must be used to determine the extent of a child's auditory function
- a test battery approach
- furnishes detailed information
- avoids drawing conclusions from a single test
- sllows for the identification of multiple pathologies
- provides a comprehensive foundation for observing a child's auditory behaviors
Pediatric Audiologic Test Protocols
- Birth through 6 months of age
- testing of infants or children should rely primarily on physiologic measures of auditory function
- ABR
- ASSR
- OAE
- case history, parent/caregiver report, behavioral observation of the infant's responses to a variety of sounds, developmental screening and functional auditory assessments should also be performed
- testing of infants or children should rely primarily on physiologic measures of auditory function
- Five months through 24 months
- behavioral assessments with VRA (visual reinforcement audiometry) being the behavioral test of choice
- OAEs, ABRs assessment when tests are unreliable
- or auditory neuropathy suspected
- 25 months - 60 months
- behavioral tests (VRA or CPA (conditioned play audiometry)) and acoustic immittance tests are usually sufficient
- speech perception tests
- Expected outcomes of pediatric audiologic protocols are extensive and include
- identification of hearing loss
- identification of auditory neuropathy, if present or of a potential central auditory processing/language disorder
- quantification of hearing status based on behavioral and electrophysiologic tests
- development of a comprehensive report of historical, physical, and audiologic findings and recommendations for treatment and mangement
- implementation of a plan for monitoring, surveillance, and habilitation of hearing loss
- provision of family =-centered counseling and education
Why Behavioral Audiologic Tests Need to Be Included in the Evaluation of All Infants and Children
- Behavioral testing is not the preferred method for evaluating hearing in infants from birth to 4 months of age for identifying hearing loss and selecting hearing aids because of
- the prolonged cooperation required from the child
- excessive test time needed
- poor frequency resolution
- poor test-retest reliability
- The behavioral audiogram provides valuable information not available from electrophysiological testing and within certain limits, it should be possible to obtain good-quality behavioral evaluations on infants and children of any age or developmental status
Steps to Take Before Initiating Behavioral Audiologic Testing of Infants and Children
Selecting the Appropriate Test Protocol
- It is essential to know the child's cognitive level and physical abilities
- Knowledge of what tasks the child is capable of performing before initiating testing is crucial
- behavioral observation audiometry (BOA) is the appropriate behavioral technique for infants from birth to 6 months cognitive age;
- Visual Reinforcement Audiometry (VRA) is appropriate for infants from 5 months to 36 months
- Conditioned Play Audiometry (CPA) is the appropriate technique for children whose cognitive age is 30 to 36 months and older
- Case history will be helpful in determining cognitive level
- Motor development can be a useful marker
- Using an inappropriate test may give the false appearance of hearing loss or yield inaccurate thresholds
- Physical condition needs to be evaluated
- If the child sucks, BOA can e implemented; Behavioral Observation Audiometry
- if the infant does not suck, it is probably not possible to obtain reliable observation audiometry responses
- VRA uses a conditioned head turn in response to presentation of a sound stimulus
- good vision
- neck control
Setting Up the Test Room
Using a Two-Room Setup
- Two-room setup with an audiologist and audiometer in one room and the child, parent and test assistant in the other
- full view of the child
- both testers need to be able to judge the presence or absence of a response
- Two testers are able to communicate
- hear directions or suggestions from the audiologist in the control room
- test assistant knows when the stimulus is being presented
- example: if a child looks toward the VRA toy when a sound has been presented, the test assistant must be enthusiastic, clapping and laughing
- the tester and test assistant must develop visual cues to ensure that they are communicating
Using a One-Room Setup
- Some audiologists use a one-room test setup
- testing can be accomplished with only one audiologist allowing more control of the test situation
- arranged so that the child cannot see the audiometer controls and does not know when the interrupter switch is being pressed
- there are times when it is convenient to have the tester and child in the same room
Obtaining a Case History
- a good case history is a valuable tool and an often overlooked part of an audiologic evaluation
- failure to obtain sufficient history information may reduce the quantity and quality of data obtained from the evaluation and diminishes the role of both the assessment and the audiologist to a technical one rather than a professional and diagnostic one
- learn about a child's development and health
- If different family members have dissimilar viewpoints this difference of opinion frequently emerges during the interview process
- provides an opportunity to observe the child and his interactions with family members and others
- develop rapport with and insights into the family
- by the end of the interview, the audiologist should have a good picture of the child's cognitive and developmental status as well as an initial estimate of the child's auditory skills
Collecting Case History Information
- Advance information is especially helpful
- However, not all families will complete forms even if they are received in advance
- the audiologist still needs to ask questions and spend time reviewing the information before initiating testing
- it extends the time scheduled for an evaluation
- The case history form should be viewed simply as a guide to the interview process