Screening, Diagnosis and Early Intervention: The Pediatric
Audiologist’s Role
Antonia Brancia Maxon, Ph.D.
NECHEAR
Karen M. Ditty, M.S.
Texas ENT Specialists, P.A.
NCHAM
Timely and Appropriate Diagnosis of Hearing Loss
Newborns screened by 1 month
Infants with hearing loss identified by 3 months
Amplification use begins within 1 month of diagnosis
Infants enrolled in family-centered early intervention by 6 months
Ongoing Audiological management - not to exceed 3 month intervals
Professionals are knowledgeable
Benchmarks (JCIH, 2000)
Newborns screened by 1 month
Currently approximately 86% of all newborns in the United States have their hearing screened at birth
The number of infants referred for diagnostic audiological evaluations has dramatically increased .
Infants with hearing loss diagnosed by 3 months
Progress has been made
Testing site may influence age of diagnosis
Geographic access to services may influence age of diagnosis
Impediments to Lowering Diagnostic Age
Audiologists lack experience with very young infants and are uncomfortable making the final diagnosis.
Facilities do not have the equipment needed to assess very young infants.
Audiologists are not familiar with clinical protocols necessary for making accurate diagnosis with very young infants.
Inadequate number of audiologists with pediatric expertise
Aids to Lowering the Age of Diagnosis
Although there are no national protocols or standards many states have guidelines for their audiologists.» These guidelines can be obtained via the following
link on the NCHAM website: http://www.infanthearing.org/states/table.html
NCHAM audiology training» Pediatric Diagnostics
» Pediatric Amplification Fitting
Pediatric Audiologist
Have the appropriate audiological equipment and protocols for testing newborns and young infants.
Can evaluate a child’s hearing within a short period of time after being contacted for an appointment.
Specializes in working with infants and young children.
Wants to work with infants and young children.
Has worked with Part C program in their state
Pediatric Audiologist
Is familiar with the procedures of the Part C system, including IFSP development and procedures for acquiring hearing aids or assistive technology.
If dispenses hearing aids:
» can make earmolds,
» has loaner hearing aids available
» provides hearing aids on a trial basis
» has resources to repair hearing aids quickly
Pediatric Audiologist
Is willing to review the test results of the audiological evaluation face to face with the family, respecting the Cultural Differences of family units.
Is willing to provide a comprehensive written report with a copy of the test findings in a timely manner.
Pediatric Diagnostic Test Battery
Comprehensive Case History
Frequency-Specific Auditory Brainstem Response
High Frequency Probe Tone Tympanometry
Transient and/or Distortion Product Otoacoustic Emissions
Behavioral Audiometry
Referrals
Frequency-Specific ABR
Accuracy of pure tone threshold estimates with tone burst ABR
High correlation (>.94) for infants and older children (Stapells, et al, 1995)
90% of ABR thresholds within 20 dB of PT thresholds with most within 10 dB
audiometric configuration does not affect accuracy of match (Oates and Stapells, 1998)
Pediatric ABR
Air conduction measures should be done with insert earphones - can affect latency
Bone conduction measures are needed to rule out conductive loss or find conductive component.
Without BC will extend time until diagnosis
Pediatric ABR-Sedation
Who and When» 4 months to 5 years
Options» conscious sedative» mild general anesthesia
Monitoring» administered and managed by nurse
– monitor O2, HR and BP– crash cart and suction available
(J. Hall, 2001)
Pediatric ABR-Sedation
Negative outcomes associated with» overdoses, drug interactions» non-trained personnel» injuries to facility (administered at home)» drugs with long half-lives (chloral hydrate,
pentobarbital)
(J. Hall, 2001)
Pediatric Immittance Measures
Provide information about middle ear status to add to BC information
May be affected by conditions in very young infant’s ears - highly compliant
Use of high frequency probe tone (800 Hz or greater) increases reliability and accuracy in young infants.
Pediatric Evoked OAEs
Infants and young children with normal hearing have robust
» transient evoked otoacoustic emissions (TEOAE)
» distortion product otoacoustic emissions (DPOAE)
TEOAEs and DPOAEs and easily measured in infants and children.
Middle Ear Effects on OAEs
Middle ear effusion may
» obliterate emission
» eliminate low frequency component
Negative middle ear pressure may
» reduce amplitude, particularly in high frequencies
•OAEs are objective evidence of healthy cochlear OAEs are objective evidence of healthy cochlear functionfunction
•The vast majority of hearing impairment in the low-risk The vast majority of hearing impairment in the low-risk population is a result of malfunction of the cochlear / outer population is a result of malfunction of the cochlear / outer hair cell system, the most sensitive and vulnerable part of hair cell system, the most sensitive and vulnerable part of the hearing mechanism tested by OAEs.the hearing mechanism tested by OAEs.
•OAEs provide meaningful information when OAEs provide meaningful information when Retrocochlear and/or auditory neuropathy are a concern.Retrocochlear and/or auditory neuropathy are a concern.
OAE SummaryOAE Summary
Behavioral Response Audiometry
Provides information about how an infant or young child uses hearing
Behavioral observation techniques can be used to give functional information
» only suprathreshold information is obtained
» will get better responses to speech than tones
Can look at amplification benefit
Amplification Assessment and Fitting
Initiate amplification process immediately after diagnosis.
Includes medical clearance
Includes earmolds - overnight mailing to get within 1 week
Does not require exhaustive audiological data
Pediatric amplification fitting
Ability to conduct real-ear measures
Scheduling flexibility and immediacy
Experience with functional measures of benefit
Basic Audiological Information Used to Fit Amplification
Hearing Sensitivity
» ABR frequency specific information - low, mid and high frequency
» Individual ear measures: insert phones
Middle Ear Status
» Tympanometry - high frequency
» BC to rule out conductive loss
Basic Audiological Information Used to Fit Amplification
Cochlear status» ABR intensity-latency function
» OAEs
Behavioral Responses» target audiogram
» speech awareness
Prescriptive Approach to Hearing Aid Fitting
Prescriptive methods designed to consider earmolds and person’s own ear canal, etc.,
Select targets (gain, output)
» real ear measures
» coupler measures
Real Ear to Coupler Difference Procedure (RECD)
The infant’s ear is smaller than an adult ear
» More SPL for same input compared to adult
» Differences can be as large as 15-20 dB
» Many hearing-aid fitting algorithms do not take these differences into account.
RECD affects estimates of:
» Threshold
» Real-ear gain and output
RECD
After the RECD is obtained, all hearing aid testing can be done in the test box
RECD values are entered into the hearing aid fitting program to provide a more accurate estimate of real-ear aided gain and output
The RECD will change as the child grows. A good rule of thumb is to obtain a new RECD when a new earmold is needed
Prescriptive Approach to Hearing Aid Fitting
Desired Sensation Level - DSL (Seewald, et al, 1996)
» Uses minimal audiometric data» Real ear measures» Adjustments for pediatric ears» Used to determine target gain and
output settings
DSL Goal
Provide children with amplified speech that is audible, comfortable, and undistorted across broadest relevant frequency range possible.
» Infant acquiring language has access to speech of others
» Infant acquiring language has access to own speech
Speech Sounds
Range from softest to loudest speech sound = 30 dB
Low frequencies carry suprasegmental, vowel, and voicing information.
High frequencies carry consonant, perceptual, and linguistic cues.
Referral to and Enrollment in Early Intervention
Know established Part C guidelines in state
Know child eligibility criteria
» automatic enrollment - diagnosed condition
» significant developmental delay
Know state guidelines for selecting a program
Enrollment in Early Intervention
Develop Individualized Family Service Plan (IFSP)» All services
– speech and language development– auditory development– assistive technology
» Goals and objectives» Timelines
Components of IFSP for I/T with Hearing Loss
Amplification provision» parent education
Audiological monitoring Development of auditory skills Communication development
» listening skills - speech perception
» speech production
» language development Monitoring middle ear status
Status of EHDI Programs: Early Intervention
State Coordinators estimate:
» Only 53% of infants with hearing loss are enrolled in EI programs before 6 months of age
» Only 31% of states have adequate range of choices for EI programs
Barriers to Early InterventionBarriers to Early Intervention
• 30-40% of children with hearing loss demonstrate 30-40% of children with hearing loss demonstrate additional disabilities that may affect communication additional disabilities that may affect communication and related development. and related development.
• Families who live in under-served areas may have less Families who live in under-served areas may have less accessibility, fewer professional resources, deaf or accessibility, fewer professional resources, deaf or hard of hearing role models, or sign language hard of hearing role models, or sign language interpreters available to assist them.interpreters available to assist them.
• A growing number of children with hearing loss in the A growing number of children with hearing loss in the United States are from families that are non-native United States are from families that are non-native English Speaking.English Speaking.
JCIH 2000JCIH 2000
Some babies are born listeners..•If we:If we:
•use the elements of an use the elements of an effective EHDI programeffective EHDI program
•use the JCIH 2000 use the JCIH 2000 Benchmarks Benchmarks
•use appropriate use appropriate diagnostic protocols and diagnostic protocols and proceduresprocedures
•refer to early interventionrefer to early intervention
•are active participants in are active participants in early interventionearly intervention