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