Txt Book Ch 64 Flashcards
How is hearing conducted?
Over 2 pathways; air and bone
What does the external ear include?
Auricle (pinna) and the
External auditory canal
How do are sounds transmitted that are transmitted by air conduction?
Sounds transmitted by air conduction travel over the air filled external and middle ear Thru vibration of the tympanic membrane and ossicles
How are sounds transmitted by bone conduction?
Sounds transmitted by bone conduction travel directly thru the bone to the inner ear, bypassing the tympanic membrane and ossicles
Normally air conduction is the most efficient pathway.
What is a way that acute external otitis is suspected?
Manipulation of the auricle does not normally elicit pain. If this,does,occur acute external otitis is suspected.
What is the weber test?
Uses bone conduction to test lateralization of sound.
A tuning fork set in motion by grasping it firmly by its stem and tapping on the examiners knee or hand, is placed on the patients head or forehead.
Conductive hearing loss
Loss of hearing in which efficient sound transmission to the inner ear is interrupted by some obstruction or disease process.
Chronic otitis media
Repeated episodes of acute otitis media causing irreversible tissue damage and persistent tympanic membrane perforation.
What does the rinne test assess?
It assesses both bone and air conduction of sound
What are results of the weber test used to determine?
Whether the pt. has conductive hearing loss ( sounds are heard better in the affected ear) or sensorineural hearing loss ( sounds are heard better in the Normal ear)
What is done in the rinne test?
The examiner shifts the stem of the vibrating tuning fork between 2 positions: 2 inches from the opening of the ear canal( for air conduction) and against the mastoid bone ( for bone conduction)
In a rinne test a person with conductive hearing loss hears what?
Hears bone conducted sound as long as or longer than air conducted sound
In a rinne test, a person with sensorineural hearing loss hears what?
Hears air conducted sound longer than bone conducted sound.
Conductive hearing loss usually results from what?
From an external ear disorder, such as impacted cerumen, or a middle ear disorder such as otitis media or otosclerosis.
What does a sensorineural hearing loss involve?
Damage to the cochlea or vestibulocochlear nerve