Concise Behavioural testing Flashcards
BOA (behavioral observational audiometry)
- Behavioural observational audiometry inst in practice
- technique without reinforcement
- age range is 0-6 months
- subjective as it depends on observers interpretation of child’s behaviour
- it doesn’t give thresholds as it detects reactions louder than the threshold but not the threshold
- useful for children with complex needs who cant participate in other tests
*Test prep:
- appropriate history
- explain the test and subjective observation
- observe the child and record the child’s responses before testing
- use child’s mode of communication
- quiet room-large soundproof booth
- accommodate wheelchair users
- ventilated
- minimal sensory stimulation
*Equipment:
- audiometer
- sound field speakers
- transducers
- Instruments: drum rattle etc
- CD player
- Songs/ sounds
*BOA test procedure:
1- mother and baby seated comfortable
2- second tester- good view of the child to monitor changes
3- present sound at an audible level
4- present sound 2-5 seconds- look for a change in behaviour
5- if it is repeatable, decrease intensity
6- decrease in 20 dB and increase in 10dB steps
7- responses can habituate quickly (unconditioned responses)
8- use no sound trials
*Indications of responses:
- eye-widening
-blinking
-changes in body movement
- searching
- vocalisations
- quieting
- head or limb reflex
- body startle
*Ensure child isn’t responding to:
- Vibrations
- Tactile sensations
- Perfumes or strong smells that might distract or influence the child’s response.
- Tips for testing;
- alternate between stimuli to maintain child’s interest + ensures accurate responses.
*Limits of BOA:
- Limited effectiveness
- Large range of acceptable responses
- Observer bias
- Parental cues
- Habituation to responses
- Baby not sleepy when testing.
DT (distraction testing)
- doesn’t provide exact thresholds
- technique without reinforcement
- 6/7- 12 months because they develop object permanence so it wont work beyond this
- DT is a hearing test where an infant turns to locate a sound stimulus
- this is a conditioned response
- BUT not sound trails to ensure there not responding to visual or non auditory cues like visual cues
- its superseded by NBHS but still used to cross-check or when child cant do other testing
- soundproof booth to minimise noise interference
- when using warble tone, apply correction factor
*Roles of staff:
DISTRACTOR:
- gets child’s attention, gets them ready for another stimuli
- observers the child WITHOUT making eye contact
- judges response validity
TESTER:
- presents stimuli at appropriate place, time & level & decides stimuli
- present stimuli at 135 degrees to the child’s ear in the horizontal plane.
- BOTH staff look for intention + unintentional cues
*Equipment:
- sound level meter and test signals
*Sound stimuli used:
- Repeated unforced “ss” sounds for testing at 4 kHz.
- Humming with minimal voice for testing at 500 Hz.
*Room set up:
- signal source at 135 degrees +-
- stimuli 1m away from child
- child sits at a low table with distractor infront and parent behind
Test steps:
1- check the baby is able to follow an object through 90 degrees.
2- Distractor:
- Gains the attention of the baby with a simple toy
3- phases out play activity
4- tester: presents the sound stimulus from behind the child for up to 10 seconds. - ENSURE, you start by presenting the sound at a quiet level, gradually increase until response and once the super threshold is determined, decrease to find the MRL
5- baby is rewarded (well done, smile, tickle) if they respond
6- distractor takes child’s attention back to the front and tester moves behind the child again
7- use ‘no sound trials’
*Minimal Response Level:
- determined when the child responds to 2/3 presentations
*Result interpretation:
- response at 30dB (A) = good enough hearing, absence of significant degree of HL
-
VRA
- 6-24 months because they get head control so it works
- technique without reinforcement
- can be both soundfiedl and ear specific using inserts
- hand held generators are used in clinics where VRA facilitators aren’t available
- purpose= A child will locate to a sound source – the orientation response- if it hears it.
- Classical conditioning: establish relationship between stimulus and reward
- Operant conditioning: reward provided when the child turns appropriately
- habituation occurs as the child becomes less interested in the sound, use interesting sounds like their name, favourite toy, richer more complex sounds
- inserts are preferred for ear specific testing as they are lighter= easier head turns & inserts reduce the need for masking =simpler test BUT you may have to recondition for inserts
*Limitations:
- Masking may not be possible
- Always the better ear responding
- Use of pure tones, which may not maintain the child’s interest.
- Equipment can be complex or expensive.
- Misalignment or offset of visual rewards can affect the child’s response.
*Test prep:
- Morning calibration
- Introductions
- History taking
- Otoscopy
- Instructions for the testing procedure
- Involuntary cueing
- Child’s ability to head turn
- Family seated behind the child being tested
- Play- keeping the child interested, but not distracted
*How visual rewards work:
- In a smoked plexi-glass cabinets
Rewards on both sides
Variety of rewards:
– Blinking lights
– Mechanical toys that are able to be illuminated and move
– Cartoons or videos
The more complex the reward the more responses that can be obtained
*Room set up:
Double-Walled Test Room:
*Soundproof to eliminate external noise.
Loudspeakers:
*Positioned at 90° to the child’s left (L) and right (R).
*Deliver frequency-specific sound stimuli.
Reinforcer Cabinets:
*Located near the loudspeakers.
*Contain visual rewards (e.g., lights or toys) to reinforce responses.
Subject (Child):
*Sits at a low table between the loudspeakers.
*Positioned centrally for consistent sound delivery.
Parent:
*Seated behind the child to provide comfort without influencing responses.
Tester 1 (Audiologist):
*Located in the observation room.
*Operates the audiometer and monitors the child’s responses via a microphone.
Tester 2:
*Observes the child inside the test room.
*Verifies behavioral responses to the stimuli.
Observation Window:
*Allows Tester 1 to observe the child’s behavior through a soundproof partition.
*Test procedure:
1- supra- threshold stimuli: 60-70dBHL at 2kHz
2- sound and reward presented at the same time
3- tester can draw child’s attention to the reinforce
5- if the child does not respond, raise stimulus level or change frequency
6- change stimulus type to NBN which may hold attention better
7- use vibrotactile stimulation (if needed): for ppl who font respond to auditory stimuli, tactile can be used for conditioning
TESTING:
1- start with bigger increments (20dB Down): this is to quickly determine the child’s response range
2- Apply 10dB down and 5dB up process can be applied closer to threshold
3- Remember efficient testing as limited attention time
4- Frequency testing order: 2kHz, 0.5 kHz, 4KHz, 1KHz= good representation of the child hearing range
LOCALISATION:
1- Begin testing by presenting narrow band noise at a level 30 dB above the child’s minimal response level.
2- Check for Asymmetric Hearing Loss.
3- Remember Sound Field Testing is Not Ear-Specific
4- Whenever possible, try to gather ear-specific information using OAEs (Otoacoustic Emissions), headphones, or inserts.
5- Ear-Specific Data is Essential for Fitting Hearing Aids.
- Results:
- successful conditioning= clear head turns
- Normal hearing= equal to or less than 25dBHL
*IF fail, whats next?
- BC testing if air conduction thresholds are raised or if sound field testing results are not within normal limits, indicating possible hearing loss as it helps test inner ear or if the sound is bypassing the outer and middle ear. USE soft headband for BC as it can be held in place if necessary
Play audiometry
- technique with reinforcement
- used for children 2-5 years because they can follow simple instructions
- Child following an instruction on how to play a game
- Waiting for a sound before responding
- Fun game so the child is engaged
- Game demonstrated before child is conditioned
- Useful when English is not their first language
- Performed in sound field or using transducers
- Initial conditioning may be easier in the sound field
- Multiple appointments may be necessary
Praise the child for correct responses and gently correct any incorrect ones. - you might need to involve the parents for the first one
*Test Steps:
1- Conditioning at Supra-Threshold Levels:- To ensure the child clearly hears the sound and learns to associate it with the task.
2- Demonstrate the task and guide the child.
3- Ensure the child provides two reliable conditioned responses before moving to testing.
4- Stimulus Presentation:
*Use warble tones or narrow band noise in the sound field.
*Use warble tones for headphones or inserts.
*Present the stimulus for 1–3 seconds.
Frequency Testing: 2kHz, 0.5kHZ, 4kHz, 1kHz
5- Complete one frequency before moving to the next.
Acceptable Response:
Record 2 out of 3 responses at the minimal level.
- No Sound Trials:
Include trials with no sound to confirm valid responses.- not sound dependent - Unconditioned Responses:
If the child cannot condition, switch to a different behavioral test.
*Additional Support:
- Condition through vibrotactile stimulation if needed.
- Advise parents/guardians to practice at home to help the child.
*Documentation:
Record results if hearing is screened.
- To avoid distractions and keep the child focused on the task.
Tymps
- objective measure of the compliance or mobility of the tympanic membrane
= it works as It assesses eardrum mobility as a function of changing air pressures in the ear canal. 4 months of age, ME resonance reaches adult levels as the structures mature. - Neonatal ME resonance is lower than adult ME resonance, meaning neonates amplify and transmit low-frequency sounds more effectively.
This occurs because neonatal middle ear structures are softer, smaller, and less stiff, including: - use a 1000Hz probe tone for infants and younger than 6 months- Provide clearer and more distinct peaks, indicating better detection of middle ear function and any abnormalities.
= if we used 226Hz= flatter less distinct tymps - use a 226Hz probe tone for adults= because this is below the natural resonance of 900Hz
- Characteristics: Peaks at 0 daPa.
Indication: Normal middle ear function. - Characteristics: Unusually high peak.
Indication: Suggests ossicular discontinuity (e.g., dislocation of middle ear bones). - Characteristics: Reduced peak.
Indication: Suggests ossicular fixation (e.g., stapes is stiffened). - Characteristics: Flat, no peak.
Indication: Suggests reduced movement due to middle ear fluid, space-occupying tumor, or other obstruction. - abnormally large volume= perforation or patent grommet
- small volume= probe is against the ear canal wall
- Characteristics: Negative pressure.
Indication: Indicates Eustachian tube dysfunction.
*Test procedure:
1- Calibrate Equipment: Ensure the tympanometer is calibrated and (check in an ear or cavity).
2- Perform Otoscopy: Inspect the ear canal to check for any obstructions or abnormalities.
3- Select Ear Tip: Use either conical or flanged ear canal tips based on the best fit.
4- Set Tympanometer: Configure the tympanometer to a 1000Hz probe tone with admittance measurement.
5- Pressure Sweep: Use a sweep direction from +200 to -400 daPa (or extend to -600 daPa if needed).
6- Pressure Change Rate: Set a fast rate of 600 daPa/sec for efficient results.
Repeat Trace:
7- Repeat the measurement if necessary, especially for abnormal or unclear results, to ensure accuracy.
*Results:
-1 positive peak= normal & also 1 negative + 1 positive s normal as the postie takes over
Neonates= no ECV value BSA gives, except flat trough is normal, positive peak from connected baslines is nomal
- infants and young child: MEP= -100 to +50daPa
Compliant/ admittance= 0.2 to 1.6
ECV= 0.4 to 1.0 cmcubed
What do high-frequency tympanometry, OAEs, and ABR test for in hearing assessments?
- high frequency= check for middle ear problems, such as fluid or pressure issues, that could affect hearing.
- OAEs (Otoacoustic Emissions): assess the function of the inner ear, specifically the cochlea, by measuring sound waves produced by the cochlea in response to stimuli.
-ABR (Auditory Brainstem Response): evaluates the auditory pathways in the brainstem, measures the brains response to sound to assess hearing and identify any issues with the auditory nerve or brainstem.
ABR
*electrode placement:
- 3 electrodes, 1 on forehead high up other 2 on mastoid of each ear.
- Headphones are also places in the babies ear. Rapid tones known as busts or clicks are sent in succession to the babies ear drum. The electrodes placed on the ear are measuring the brainstem response.
Condition| Baby needs to be asleep. No other electrical waves distorting the equipment. The electrodes need to be sticky to stay put on the babies head.
- assesses degree of HL,It is usually done with behavioural tests in a a battery test because ABR can tell you the degree of HL
Advantages:
- More robust than AOE
- Tests up to the brainstem
- Does not need professionals
- Gives automated response
Disadvantages:
- Not cost effective
- Takes a long time
- The child has to be asleep
- Can be impacted by electrical devices
OAE
Uses:
-*Newborn Screening:
- Used in the NHSP as the initial screening test for well babies.
Well babies can be discharged if OAEs are clear, provided no risk factors are present and there are no parental concerns.
*Follow-Up Testing:
- OAEs are quicker than ABR and do not require the baby to sleep.
- Should be used alongside ABR for babies in SCBU (Special Care Baby Unit).
- Useful indication of normal cochlear function in difficult-to-test children, those with additional needs or
suspected non-organic hearing losses
- OAEs helpful to confirm good OHC function and reassure parents
Advantages:
- Automated
- Does not require specific professionals
- Cost effective
- Produces quick results
*Limitations:
- Only indicate outer hair cell function, not normal hearing.
- Can be affected by fluid in the babies ear
- Baby should be quiet so also acoustic influences (baby crying, outside noise)
3.does not test beyond the cochlea
- Babies who pass OAEs may still have Auditory Neuropathy Spectrum Disorder (ANSD), though this is unlikely in well babies.
- speech testing provides better indication of actual hearing than OAEs and ABRs
*Pass Criteria: Green ticks
- bottom= noise, top= SNR
- Signal-to-Noise Ratio (SNR) ≥ 6 dB for the majority of frequency bands (e.g., 1 kHz, 1.5 kHz, 2 kHz, 3 kHz, and 4 kHz).
- good equal spread of frequencies should be present and not ringing at the stimulus
- the stimulus should be finished b 4ms to into interfere with the recording.
- The OAE response is clearly above the noise floor.
- Reproducibility and stimulus stability should be within acceptable limits (≥ 70%).
- Partial OAEs= 3 bands = pass= clear response.
- No clear response - noise needs to be lower than -5 INC inclusive- 2 clear responses
*Characteristics:
- OAEs are large in neonates with good high-frequency response.
- Present from birth, even in pre-term babies.
*Considerations for Testing:
- Reduced success rate in the first 2 days of life due to amniotic fluid in the ear.
- OAEs are usually absent when middle ear fluid is present.
- Testing is quick to perform.
- The baby must be settled and quiet (not necessarily asleep).
- Results can be affected by noise from the child or the environment.
- A good probe fit is essential for accurate results.
