SLHS 460 Exam 3 Acoustic Reflex Patterns & Physiological Tests

What neural pathways are involved in the acoustic reflex?

right/left

ipsi/contralateral

What does the acoustic reflex do to the admitance of the middle ear?

lower sound pressure levels in the ear canal are associated with greater acoustic admittance and more energy flow through the middle ear system

Patterns of reflex for unilateral loss

only affects half of the reflexes

Patterns of reflex for bilateral loss

affects all of the reflexes

Patterns of reflex for conductive loss

absent

Patterns of reflex for cochlear loss

obtained at lower SL

Patterns of reflex for retrocochlear loss

absent

What is the Auditory Brainstem Response (ABR)?

electrical activity evoked by very brief sounds that originates from the 8th nerve or auditory portions of the brain stem. It consists of 5 waves and is usually recored from the surface of the scalp/external ear. It is used in hearing testing of infants and young kids and in detection of auditory abnormalities affecting the auditory nerve and brain

What level of the auditory system does ABR test up to?

brainstem

What frequency regions does the ABR test?

all frequency regions

What aspects of the ABR are used in diagnosis?

- ABR provides objective frequency-specific thresholds that help to estimate the degree and configuration of hearing loss

- ABR is also useful in determining the type of hearing loss

- the patient's auditory threshold corresponds to the intensity elvel where ABR wave V disappears

What are OAEs?

sounds measured in the external ear canal associated with activity of the OHCs

What level of the auditory system do OAEs test up to?

cochlea