Diagnostic Pediatric Audiology from Birth to Intervention

1. Diagnostic Pediatric Audiology from Birth to Intervention Karen M. Ditty, M.S. NCHAM Antonia Brancia Maxon, Ph.D. NECHEAR NCHAM

2. Timely and Appropriate Diagnosis of Hearing Loss • Newborns screened by 1 month • Infants with hearing loss diagnosed by 3 months • Amplification use begins within 1 month of diagnosis Benchmarks (JCIH, 2000)

3. Timely and Appropriate Diagnosis of Hearing Loss • Infants enrolled in family-centered early intervention by 6 months • Ongoing audiological management - not to exceed 3 month intervals • Professionals working with these infants are knowledgeable about all aspects Benchmarks (JCIH, 2000)

4. Newborns screened by 1 month • Approximately 90% 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 .

5. Infants with hearing loss diagnosed by 3 months • Progress has been made however it is affected by • Testing site may influence age of diagnosis • Goal is often met in hospital clinics • Less likely in non-hospital centers • Geographic access to services may influence age of diagnosis • Rural communities are less likely to meet the goal

6. Impediments to Lowering Diagnostic Age • Audiologists lack experience with very young infants • uncomfortable making the final diagnosis. • Defer to and refer for second opinion • Facilities do not have the equipment needed to assess very young infants. • Frequency specific ABR • AC and BC ABR • High frequency tympanometry

7. Impediments to Lowering Diagnostic Age • Audiologists are not familiar with clinical protocols necessary for making accurate diagnosis with very young infants. • Do not have “norms” • Cannot “read” ABR for this population • Inadequate number of audiologists with pediatric expertise • No academic training to work with very young infants • No clinical training to work with very young infants

8. 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

9. Aids to Lowering the Age of Diagnosis • Audiologists can get training through continuing education provided by national associations • NCHAM audiology training • Pediatric Diagnostics • Covers the initial diagnostic procedure • Pediatric Amplification Fitting • Covers behavioral assessment, hearing aid selection, fitting and validation and cochlear implants

10. 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

11. 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

12. 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. • Is willing to continue to explain results at follow-up evaluations

13. Pediatric Diagnostic Test Battery • Comprehensive Case History • Frequency-Specific Auditory Brainstem Response • High Frequency Probe Tone Tympanometry • Transient and/or Distortion Product Otoacoustic Emissions • Hearing aid Fitting with Real Ear Measurements • Behavioral Audiometry • Referrals

14. Comprehensive Case History

15. Frequency Specific Auditory Brainstem Response • Air Conduction Clicks • Abrupt or rapid onset of a broad frequency bandwidth . • Greatest agreement in the 2000-4000Hz frequency range. • Not enough information across the frequency range • Low frequencies absent

16. Frequency Specific Auditory Brainstem Response • Tonebursts • Provides information for narrower frequency regions • Better relates to pure tone audiogram • Bone-Conducted Clicks • Should get when either the click or 500-Hz tonebursts responses are not present at expected normal levels.

17. 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)

18. Frequency Specific Auditory Brainstem Response • Auditory Steady State Response (ASSR) • An electrophysiologic response, similar to ABR • Generated by rapid modulation of “carrier” pure tone amplitude or frequency. • Signal intensity can be as high as 120 dB

19. Frequency Specific Auditory Brainstem Response • Auditory Steady State Response (ASSR) • Done in conjunction with ABR Clicks, or on a separate occasions • Major advantage is it estimates severe-to-profound HL • Best used in conjunction with ABR and tone burst testing.

20. ABR (Click and Tone Burst) versus ASSR: Clinical Application • Advantages • Estimates normal hearing • thresholds • Ear-specific BC findings • Diagnosis of AN • Estimates severe to • profound HL • Disadvantages • Can’t estimate profound HL • Skilled analysis required • Limited BC intensity levels • No ear-specific BC findings • Requires sleep or sedation ABR ASSR R. Ruth, 2003

21. Pediatric Sedation for ABR • 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)

22. Pediatric Sedation for ABR • Negative outcomes associated with • overdoses, drug interactions • non-trained personnel • injuries on the way to facility (administered at home) • drugs with long half-lives (chloral hydrate, pentobarbital) (J. Hall, 2001)

23. Pediatric ABR summary • Air conduction measures should be done with insert earphones • Headphones can affect latency of waveform • Bone conduction measures are needed to rule out conductive loss or find conductive component. • Use B-70 bone vibrator • Use mastoid placement

24. Pediatric ABR summary • Use earlobe inverting electrodes • Use alternating tone burst to minimize artifact • A slower rate (e.g., 11.1/sec) enhances Wave I • Begin testing near maximum intensity (50 dB nHL) • Allows good waveform to be seen • Identify Wave I in ipsilateral ear to verify test ear • Plot I-L function of Wave V

25. Pediatric ABR summary • Air conduction measures should include frequency specific tone bursts and/or ASSR as part of a battery of electrophysiological tests. • Of the audiological test battery, only an ABR can help determine an auditory neuropathy case; therefore, ASSR should not be performed alone, but as part of a battery of electrophysiological tests.

26. High Frequency Probe Tone Tympanometry • Tympanometry provides information about middle ear status • add information to BC results • May be affected by conditions in very young infant’s ears • Ear canal and eardrum are very compliant • Use of high frequency probe tone (800 Hz or greater) increases reliability and accuracy in young infants.

27. Transient & Distortion Product Otoacoustic Emissions • Infants and young children with normal hearing have robust • transient evoked otoacoustic emissions (TEOAE) • distortion product otoacoustic emissions (DPOAE) • TEOAEs and DPOAEs are easily measured in infants and children.

28. 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

29. OAE Summary • OAEs are objective evidence of healthy cochlear function • The vast majority of hearing impairment in the low-risk population is a result of malfunction of the outer hair cells • the most sensitive and vulnerable part of the • hearing mechanism tested by OAEs. • OAEs provide meaningful information when retrocochlear lesions and/or auditory neuropathy are a concern.

30. Amplification Assessment and Fitting • Initiate amplification process immediately after diagnosis. • Includes medical clearance • Federal regulation - ENT • Includes earmolds • overnight mailing to get within 1 week • continue to remake to avoid fitting problems

31. Pediatric amplification fitting • Does not require exhaustive audiological data • Target audiogram • Individual ear information • Ability to conduct real-ear measures • Scheduling flexibility and immediacy • Experience with functional measures of benefit

32. Real Ear to Coupler Difference Procedure (RECD) • The infant 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

33. Real ear measurement • The insert phone is coupled to the earmold • The probe microphone is placed into the ear canal • The earmold is inserted into the ear • Test stimulus is presented • Total test time 5-10 minutes per ear

34. 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

35. 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

36. Basic Audiological Information Used to Fit Amplification • Cochlear status • ABR intensity-latency function • OAEs • Behavioral Responses • target audiogram • speech awareness

37. Behavioral Response Audiometry • Provides information about how an infant or young child uses hearing • Behavioral observation techniques can be used to give functional information • Sometimes only suprathreshold information is obtained • will get better responses to speech than tones • Can look at amplification benefit

38. Behavioral Response Audiometry • Look at amplification benefit • Need to provide speech at greater than detection level • Cannot learn language with threshold-only information • All of normal conversational level speech needs to reach child through amplification

39. Speech Sounds • Range from softest to loudest speech sound = 30 dB • “th” – “ah” • Low frequencies carry suprasegmental, vowel, and voicing information. • High frequencies carry consonant, perceptual, and syntactic cues.

40. 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

41. Enrollment in Early Intervention • Develop Individualized Family Service Plan (IFSP) • All services • speech and language development • auditory development • assistive technology • Goals and objectives • Timelines

42. 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

43. Status of EHDI Programs Early Intervention • Many of the programs in the current system designed to serve infants with bilateral severe-profound losses • BUT, majority of those identified have mild, moderate, and unilateral losses • Programs and professionals not appropriate for children and families • Therefore, Part C of IDEA is severely under utilized

44. 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

45. Barriers to Early Intervention • 30-40% of children with hearing loss demonstrate additional disabilities that may affect communication and related development. • Families who live in under-served areas may have less accessibility, fewer professional resources, deaf or hard of hearing role models, or sign language interpreters available to assist them. • A growing number of children with hearing loss in the United States are from families that are non-native English Speaking. JCIH, 2000

46. Pediatric Audiology • Pediatric Audiology with newborns and young infants can be challenging!

47. Pediatric Audiology • But also rewarding!

48. Some babies are born listeners.. • If we • use the elements of an effective EHDI program • use the JCIH 2000 Benchmarks • use appropriate diagnostic protocols and procedures • refer to early intervention • are active participants in early intervention