Fundamental Components of Hearing Aid Fitting for Infants. Josephine Marriage PhD

Transcription

1 Fundamental Components of Hearing Aid Fitting for Infants Josephine Marriage PhD

2 Neonatal Hearing Screening Screening efforts have far out stripped our habilitation efforts, leaving parents with diagnosis but without support David Luterman

3 Case study 1 Week 1 - Failed NSP OAE Week 4 Failed retest OAE Week 6 - Diagnostic click ABR. Passed 30 db Lt Mother happy, father convinced hearing loss 8 months health visitor Distraction test (DT). Pass 2 nd tier community clinic DT Pass Audiology DT pass

4 Parents unsure. Second opinion 11 months 2 nd opinion hearing impairment 16 months audiology review with VRA full confidence in staff and previous results Results showed significant hearing loss - no results given on extent of HL. 2 x ABR under GA 21 months: Referral to Cochlear implant dept Implanted at 2 years 1 mo. Aetiology Connexin yrs 6 mo. No local auditory habilitation, no speech Mother: WE HAVE HAD NO CHOICES

5 NHSP Early diagnosis needs a new management model Parents are main agents for auditory management in first year of life New dynamic between family and professionals to enable: Neural development through stimulation (HA) Auditory learning (through plasticity) Communication development Empowerment of family, development of child

6 Thus NHSP confers Responsibility on professionals to provide: competent sensitive timely management to family without pre-judgement. To enable development of HI child within family. The child is the product of this process (Luterman)

7 Four Components of Audiological Management 1. Early identification and definition of hearing levels (LB) 2. Provision and verification of effective amplification (HD, RS, SS) or CI referral 3. Confirmation of site of impairment (AN) 4. Assimilation of meaning to audible sounds Aiming for audiological certainty and CI referral around 6 months of age

8 Auditory Brainstem Response (ABR)

9 1 Assessment of hearing levels Objective tests : application of protocol

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11 Cross check principle Audiological Assessment (with/without amplification) Birth to 4 months 5 to 8 months 9 to 12 months Freq. Spec. ABR VRA VRA OAE Immittance/ARTS Behav Obs High Freq Tymps Behav Obs vocalisation Behav Obs Specialist ABR Speech detect

12 Otoacoustic Emission recording

13 How to derive audiological certainty for effective hearing management? Need multiple measures with consistency across results: 1. Objective tests ABR/ASSR/CERA/OAE 2. Behavioural tests I) Unaided measures (VRA audio) ii) Aided measures (REM, detection) 3. Structured Observation eg MAIS/ESP Habilitation input, vocalisation, parent report

14 Behavioural Assessment of Hearing 4 months to 2 years: Must have reliable, ear specific, AC, BC, non-subjective test technique

15 Behavioural Hearing Assessment Different to structured observation (ESP/MAIS) Response must be consistent and repeatable Every observable response demonstrates what child CAN hear (with and without HA) for parents Allows parents to see early hearing behaviours Empowers parents to see and respond to early communication attempts by child Feeds in to decision-making on further referral

16 Review of techniques Distraction Test (DT) is not a diagnostic test technique Dr Jerry Northern notes that the use of distraction testing in the UK has stopped progress in applying modern methods of hearing assessment Behaviour observation audiometry (BOA) Visual Reinforcement Audiometry (VRA) Play Audiometry from 2 years (PTA)

17 VRA from 4 months benvra.avi benvra2.avi

18 Hearing threshold information derived across test techniques Looking for a consistent pattern of results across 3 behavioural measures (+ 2 objective ABR/OAE). All obtainable in one or two appointments UNAIDED 1. Freefield VRA 2. Separate ear VRA thresholds (AC audio) 3. Bone conduction (Unmasked BC audio) AIDED 4. Hearing aid output AAI 5. Warble tone or NBN Aided thresholds 6. Ling Aided thresholds

19 VRA Audiogram (11 months old) Audiogram db HL Frequency in Hz Right ear Unmasked BC Left ear Left BC

20 Difference between audiometry and VRA results

21 2. Provision and verification of effective amplification Full audiometry (BSER and VRA) Hearing Aids Ear moulds, fast turnaround Closely fitting deep moulds Take impressions and keep them Get non-audiologists trained for impression-taking

22 Ask parents to photo and send so know where to build up

23 3. Full definition of site of impairment and aetiology Auditory Neuropathy OAE present and ABR absent/abnormal Usually H A amplification not giving consistent improvement in functional hearing post-synaptic neural impairment AN no longer meaningful term OAE present is no indication for longer time period of watchful waiting if IHC loss. Use ABR protocol Need early (< 6 month) referral to cochlear implant assessment

24 4. Constant monitoring of responses with HA in daily life Establishing early use of hearing aids Major impact on family and child Needs to be supported by seeing that the child is more responsive with HAs If only associated with acoustic feedback and child being unsettled, hearing aid use becomes less

25 Development of sound understanding HST Set up Specific times for sound recognition Baby in appropriate state: awake, comfortable Presentation of audible, meaningful sounds (not Ling sounds, but voice, toy, knock) in dialogue Context of listening, looking, interaction Associating detection of sound to meaning through family Change type of sound or context Develop new sound awareness and vocalisations

26 Observation of hearing behaviours crucial part of monitoring HAs Seeing child in normal listening environment (ToD, AVT, SLT) with family members Provides information about low frequency hearing Demonstrates benefit of hearing aids Gives indication of uncomfortable loudness levels Hugely positive for parents and families If no responses are seen, ToD must feed this back to Audiologist.

27 Ling 5 sound detection to speech testing raffetyrapt.avi

28 Paediatric Audiology in NHSP It s about team working to bring components together and the major players are the child in the family