Pediatric Assessment
Otoscopy
Verify clean external auditory canals and note any abnormalities either inside or outside the ear
Tympanometry
Purpose: To assess middle ear (ME) function and identify need for medical management
Purpose: To assess impact of middle ear (ME) status on threshold information
Purpose: To assess impact of middle ear (ME) status on threshold information
- Infants under 6 months - 226Hz for volume and 1000Hz for mobility of tympanic membrane
- Infants over 6 months - 226Hz
Acoustic Reflexes
- 90 dB screen at 1000 Hz is acceptable to confirm presence or absence of acoustic reflexes – use caution if tympanometry is abnormal
- Use the same probe tone as the tympanogram
DPOAEs
- Screening is appropriate if child is moving or uncooperative
- Select a diagnostic DPOAE protocol. A screening protocol is
appropriate if time is limited or child is
moving. - Use the Boystown Extended norms (95th percentile criterion) to determine presence of the emission.
ABR
Purpose: To assess neural synchrony along the ascending auditory pathways through the level of the brainstem
Priority: Baby may wake at any time, Rule out ANSD, Obtain adequate information to proceed with amplification, Replicate
Priority: Baby may wake at any time, Rule out ANSD, Obtain adequate information to proceed with amplification, Replicate
- This is not a true measure of hearing sensitivity but a best estimation of hearing threshold levels in infants
- Objective measure (not influenced by behavior)
- Frequency specific
- Ear specific
- Natural sleep is preferred
- 2 channel recording
- High forehead (FPz)/Top of scalp (Cz)*preferred
- Lower forehead (GND)
- M1
- M2
- Neurodiagnostic ABR
- Use a click stimulus at 80 dBnHL – 13.1 cps for >1000 averages using
a rarefaction polarity (to compare against Gorga norms) - Switch to condensation polarity and record.
- If a response is not present at 80 dBnHL, increase stimulus intensity
and record. Also consider slowing the click rate to improve waveform
morphology. - Mark waveforms
(including cochlear microphonic, if applicable) and comment on morphology. - Analyze latencies
- Absolute wave latencies – I, III, V
- Interpeak wave latencies – I-III, III-V, I-V
- Repeat for opposite ear
- Use a click stimulus at 80 dBnHL – 13.1 cps for >1000 averages using
- Test for ANSD
- If the rare / con click response is abnormal, change polarity to alternating and record
- If a cochlear microphonic is present using rarefaction / condensation
polarities and primary waveforms are absent, record rarefaction and
condensation runs again with the insert tubing pulled out of the
transducer box. - This
will help distinguish the cochlear microphonic from stimulus ring. - Note “Stimulus on, but insert out of ear
” on the waveform printout. - It is helpful to overlay the rarefaction and condensation runs on the
waveform printout to highlight the cochlear microphonic reversal
- Threshold ABR Testing
- Threshold ABR testing
- Begin with 2000 Hz toneburst at 80 dBnHL
- If present, mark wave V and decrease by 40 dBnHL. Begin threshold
estimation. - Use bracketing method
- Mark wave V for each present response
- Replicate, replicate, replicate
- 10 dBeHL (using correction factors) is considered normal for peds and 20
dBeHL for adults. Do not test lower - Repeat for other ear
- After 2000 Hz has been completed, proceed to 500 Hz, 4000 Hz, and
finally 1000 Hz. Consider additional frequencies. - Record ABR thresholds and estimated hearing thresholds on the ABR
worksheet - Print latency-intensity functions with report
- Latency Intensity Function
- As intensity decreases, the latency of wave V increases
- Bone Conduction ABR
- Bone conduction ABR
- If air conduction thresholds are elevated, bone conduction testing is
indicated to aid in determining type of hearing loss. - Use a click stimulus (alternating polarity at 11.1 cps), unless 500 Hz is
indicated - Be certain to start your stimulus presentation at a softer level (ie. 55
dBnHL), to avoid waking the baby (as a result of stimulus volume or
oscillator vibration). - Complete threshold
search. - Record threshold and estimated threshold on the ABR worksheet
- Typical Follow Up is 2 - 6 weeks
ASSR
- Auditory Steady State Response
- If a hearing loss is suspected, specifically in a severe to profound hearing loss range, complete frequency specific threshold search using ASSR due to ABR intensity limitations
Case Study
- Dx
- No Response ABR
- Absent DPOAE
- Flat HF Tympanometry
- Tx
- Refer to ENT for evaluation of ME function
- Re-evaluate at 6 months
- Follow up
- Normal Tympanometry
- Present DPOAE
- No Response ABR
- Large Cochlear Microphonic Present
- Dx
- ANSD