INNER EAR & COCHLEA
The bony labyrinth is filled with this fluid.
perilymph
The ear canal is approximately this long.
2.5–3 cm
The outer ear acts as this to increase sound energy.
resonator
The membrane separating the outer and middle ear.
Tympanic membrane
The ossicle attached to the tympanic membrane.
malleus
The membranous labyrinth contains this fluid.
endolymph
The lateral one-third of the ear canal is made of this tissue.
cartilage
The outer ear amplifies sound by approximately this amount.
10-15 dB
The central depression on the tympanic membrane.
Umbo
The ossicle whose footplate contacts the oval window.
stapes
This cochlear chamber contains endolymph.
scala media
The medial two-thirds of the ear canal are composed of this.
bone
These frequencies are amplified most by the outer ear.
Speech frequencies
The stiff, primary vibrating portion of the tympanic membrane.
pars tensa
The primary purpose of the ossicles.
impedance matching
The membrane responsible for frequency tuning.
basilar membrane
This substance in the ear canal provides protection against debris and microbes.
cerumen (earwax)
The outer ear helps localize sound especially in this plane.
The vertical plane
The air-filled cavity in the temporal bone that houses the ossicles.
tympanic middle ear cavity
This muscle reduces tympanic membrane vibration and is innervated by CN V.
tensor tympani
The sensory organ of hearing located in the cochlea.
organ of corti
The ear canal boosts sound most effectively in this frequency range.
2-4kHz
Directional filtering by the outer ear helps with this auditory skill.
Sound localization
The tube that equalizes air pressure between the middle ear and nasopharynx.
The auditory Eustachian tube.
This muscle is responsible for the acoustic reflex and is innervated by CN VII.
stapedius