Flashcards in The Physiology of Hearing Deck (10)
Describe the pathway of hearing
How do the cochlea help with hearing?
Hair cells within the Organ of Corti produce electrical activity (endolymph, perilymph)
This activity becomes a neural impulse and travels to the brain via the cochlear nerve VIII
Explain the Vestibule and Semicircular Canals and their function
plus saccule, utricle
hair cells and otoconia produce electrical activity
This activity becomes a neural impulse and travels to the brain via the vestibular nerve VIII
What two features combine to form sound?
Describe the clinical significance of sound intensity
0 decibels is the quietest sound you should be able to detect between 18-20
-Threshold = 0db
-Pain threshold = 130 db
Describe the clinical significance of sound frequency
Speech range is between 500Hz and 2000Hz
8000 outside human range e.g. dogs
Conductive losses tend to predominate in low frequencies
Sensorineural losses tend to predominate in high frequencies
What parts of the Cochlea deal with high and low frequency?
Basal turn = high frequency
Apical turn = low frequency
What is audiometry?
A subjective test involving the patient and audiologist
Measures amplitude or intensity of sound and frequency
What is Tympanometry?
Measure of tympanic membrane compliance involving middle ear and ear canal pressure
Because of Eustachian tube function canal pressure should = middle ear pressure
Useful to detect:
-Eustachian tube dysfunction
-Middle ear effusion (glue-ear)