Pediatric/Objective Testing Flashcards
Electroacoustic measures
Electroacoustic measures: immittance
•Clinical applications
•Concepts and equipment
•Middle ear analysis
•Static acoustic compliance
•Tympanometry
•Acoustic reflexes
Electrophysiologic measures
•Auditory evoked potentials (ABR)
•Otoacoustic emissions (OAE)
•Otoacoustic emissions (OAE)
•Otoacoustic emissions (OAE)
•Types
•Components
•Clinical applications
•Auditory evoked potentials (ABR
•Auditory evoked potentials (ABR)
•Function and clinical applications
•Basic components
•Clinical montage
Adjustments to Testing
We still need to get pure tone and speech information, even if the person cannot respond traditionally
•Why? Quality of life—but (more importantly) language acquisition!
Behavioral Testing
Pediatrics/Special Needs
• Soundfield Testing
• Altering test procedures as needed
• Behavioral observation audiometry (BOA)
• Visual reinforcement audiometry (VRA)
• Play audiometry
• Case history can be important here
• Activities of daily living (ADL) important too
Hearing tests for the infant
The use of the above EDAE and ABR tests, PLUS
Behavioral audiometry
Auditory signal presented to an infant produces a change in behaviour e.g alerting,
cessation of an activity or widening of eyes. •
Moro’s reflex: sudden movement of limbs and extension of head in response to sound of 80-
90 dB. •
Cochleo-palpebral reflex: Child responds by a
blink to aloud sound. •
Cessation reflex: Infant stops activity or starts crying in response to sound 90db
Issues in Speech Audiometry
• Speech Materials for the Pediatric Population
Speech Materials for the Pediatric Population • Ensure that speech material given is within the child’s receptive
vocabulary
• Age-appropriate response required
• Body parts, colors, picture boards, etc.
Immittance
Immittance: a measure of how readily a system can be set into vibration by a driving force
•A physical characteristic of all mechanical vibratory systems
Most conductive hearing losses tend to stiffen the middle ear
•The effect of stiffness is lessened as stimulus frequency increases. Therefore, most conductive hearing losses are centered around low-frequency decrease of hearing sensitivity
•Frequencies higher than 2000 Hz have negligible contribution to the conductive system.
Admittance
Admittance: total energy flow through a system
Impedance
Impedance: total opposition to energy flow
Immittance Audiometry: Concepts
At high air pressure (+200 daPa), the TM is pushed into the middle ear space
•At low air pressure (-200 daPa), the TM bulges out
•By changing the air pressure against the TM, we make this change of TM compliance happen until the TM reaches a point of resonance (the 0 point)
Equipment for tympanometry
Middle
Ear
Analyzer
Middle Ear Analyzer: Components
3 tubes: pure-tone generator, air pump, microphone
Ear canal volume (ECV)
Ear canal volume (ECV)
•Varies with age and gender
•Children: 0.3 cm3-1.2 cm3
•Adults: 0.6 cm3-2.0 cm3
•Possible causes of large ear canal volume include large ears and TM perforations
•Possible causes of small ear canal volume include atresia and excess cerumen
Tympanometry
Purpose: to determine the point and magnitude of greatest compliance of the tympanic membrane
•Generally conducted with a low-frequency probe tone of either 220 Hz or 226 Hz at about 70 dB SPL
Normal tympanogram
Normal tympanogram
•X-axis: peak pressure between -100 daPa to +100 daPa
•Y-axis: TM compliance between 0.3 cm3-1.7 cm3