Anatomy - Hearing

endolymph is composed of ______

potassium

_ in ____ children born with profound hearing impairment; _ in _____ will acquire deafness in early childhood

1 in 1000 2 in 1000

what decibels is a mild hearing loss

16 to 40

what decibels is a moderate hearing loss

41 to 55

what decibels is a moderate/severe hearing loss

56 to 70

what decibels is a severe hearing loss

71 to 90

The nerve impulses are passed on to the ________ and then transmitted to the ______ area of the brain

8th cranial nerve auditory

what decibels is normal hearing

< 15 dB

what decibels is a profound hearing loss

> 91 dB

Tonotopicity- outer bands of this nerve carry high frequency information; inner bands, low freq

Auditory Nerve (VIII)

this membrane is narrow and stiff at the base (high freq) and wider and less stiff at the apex (low freq)

Basilar Membrane

what type of hearing loss has problems in the outer or middle ear with the inner ear being normal?

Conductive Loss

acts like our body's spectrograoh - info about freq, intensity, and time. different parts of lobe respond to different freq

Heschyl's Gyrus (Temporal Lobe)

What kind of sounds stimulate the base of the Organ of Corti?

High frequency sounds

caused by excess fluid in the inner ear

Meniere's Disease

Essentially, the tensor tympani and stapedius muscle do what?

Not allow the tympanic membrane and ossicular chain to move as much

bathed in endolymph in the basilar membrane most important structure of hearing

Organ of Corti

What is the physiology of hearing? *definitely going to be an essay*

Sound waves are directed by the pinna into the external auditory meatus Waves strike the eardrum, causing it to vibrate The eardrum is connected to the malleus, moves the ossicles back and forth As the stapes moves, it pushes the oval window in and out The movement of the oval window makes waves in fluid in cochlea Pressure of the waves causes movement in the hair cells in the Organ of Corti The movement of the hair cells generates nerve impulses The nerve impulses are passed on to the 8th CN, and transmitted to the auditory area of the brain

Origin: posterior wall of the middle ear Insertion: Neck of stapes Stiffens the ossicular chain to reduce its vibrations

Stapedius Muscle

external auditory canal is narrow

Stenosis

Names of the three semicircular canals

Superior Horizontal Posterior

Origin: cartilaginous and bony margins of auditory tube Insertion: Handle of Malleus Tenses the eardrum to reduce its vibrations

Tensor Tympani

What is the tonotopic of the acoustic nerve?

The nerve's outer bands carry high frequencies. The nerve's inner bands carry low frequencies.

what is atresia? not important but helps me understand aural atresia

a closure where there shouldn't be one

the outer ear collects ____ energy

acoustic

carries electrical impulses from the cochlea to the brain

acoustic nerve

cranial nerve VIII

acoustic nerve

quick buildup of fluid/pus results in pain and possible rupturing of ear drum causes fever and vertigo

acute otitis media

Meniere's disease generally occurs in ______ and is ______

adults unilateral

sound waves travel through the air to the outer ear and are transmitted through the middle ear to the cochlea

air conduction

Air is conducted into the inner ear by: (2)

air conduction bone conduction

the middle ear is an ____ ____ cavity

air filled

We normally hear our own voice through a combination of...

air-bone conduction sounds

bone is less effected

air-bone gap

discrepancy between air conduction and bone conduction

air-bone gap

Profound SHL may have a severe effect on the acquisition of speech and language; ____________ may be affected

articulation

an expert in hearing and its disorders

audiologist

The study of hearing, its disorders, and the measurement and management of those disorders

audiology

instruments that are used to measure hearing loss - electronic devices that generates and amplifies pure tones at various frequencies

audiometer

external ear canal is completely closed

aural atresia

with central auditory hearing loss, ______________________ may make it difficult to understand speech

background noise

the three semicircular canals help to maintain _______, ____ , and ____-

balance posture and movement

floor of scala

basilar membrane

With mixed loss, bone conduction is ______ than air conduction threshold, but both indicate loss

better

a _____________ creates an airtight middle ear; soon the air is thinned out and the pressure is reduced

blocked Eustachian Tube

With a conductive hearing loss, there is always some hearing left because of the ___ _____ Therefore, a person with conductive hearing loss can hear his/her own speech well.

bone conduction

because the inner ear is damaged with sensorineural loss, _______________ also may be impaired

bone conduction

bone oscillator on skull; to assess the sensorineural portion of the auditory mechanism when the sound strikes the bones of the skull, the bones vibrate and stimulate the fluids in the inner ear

bone conduction

vibrations of bone cause movement int he fluids of the inner ear

bone conduction

2 kinds of labyrinths in the middle ear

bony (temporal bone) membranous

includes the brainstem where the auditory nerve terminates or areas of cortex responsible for filtering and interpreting sound

central auditory hearing loss

with central auditory hearing loss, it's caused by lesions to the _________________________

central auditory system

ear wax

cerumen

what 2 things found in the outer ear that helps to protect?

cerumen cilia

long term infection painless but foul smelling discharge from ear treatment : drugs and surgery expect speech and language delays

chronic otitis media

small hairs

cilia

the _________ is a primary inner ear structure of hearing

cochlea

tonotopicity - different parts of the cochlea respond to different frequencies

cochlea

what are the things called you can get when you have sensorineural hearing loss to possibly hear again

cochlear implants

so with central auditory hearing loss, generally the person hears but does not understand speech under certain conditions, such as _________________________

competing stimuli

absent external canal occurs in some syndromes like Down Syndrome, Treacher Collins

congenital atresia

cannot hear or understand conversational speech under normal circumstances

deaf

treatment of otitis media?

drugs, surgery

area of eardrum vs. area of oval window - increases sound pressure significantly

eardrum/oval window

Mechanical impulses from the middle ear are converted to _______ impulses in the inner ear

electrical

positively charged fluid

endolymph

What is the job of the eustachian tube?

equalize pressure and aerate the middle ear

what connects the middle ear to the nasopharynx?

eustachian tube

leads to the eardrum

external auditory canal

tube resonator - enhances high frequencies

external auditory meatus

infections that result in swelling of the ear canal (swimmer's ear)

external otitis

sensorineural hearing loss is not the same for all _______

frequencies

hearing loss between 16-75 dB

hearing impairment

the lowest intensity of a sound that will stimulate the auditory system

hearing level

Symptoms of meniere's disease

hearing loss vertigo tinnitus

The acoustic nerves outer bands carry ____ frequencies.

high

SHL is greater for ________ frequencies than the ________ frequencies

higher, lower

Sound waves are directed by the _____ into the ____ _____ ____

pinna external auditory meatus

prenatal causes of SHL

inheritance maternal illness drug use

otosclerosis is usually ___________

inherited

presbycusis is loss in the ____ ear, involving the _th nerve, and it is _______ _______

inner 8 cortical degeneration

Whats one specific thing a doctor will do for a blocked Eustachian tube?

insert tubes through the tympanic membrane to ventilate it

Speaking problem is one of _______: person tends to speak too softly, especially in background noise.

intensity

the inner ear is a system of interconnecting tunnels called ______

labyrinths

the acoustic nerves inner bands carry ___ frequencies

low

What kind of sounds stimulate the apex of the Organ of Corti?

low frequency sounds

what are the names of the three bones that make up the ossicular chain?

malleus incus stapes

With central auditory hearing loss, there might be no significant peripheral hearing loss so routine tests...

may not reveal a problem

the middle ear changes acoustic energy to ______ energy

mechanical

The Organ of Corti is responsible for transduction of ____ energy into ____ energy since it contains thousands of hair cells that respond to sound

mechanical energy electric energy

How do you treat a blocked Eustachian tube?

medical or surgical means

impedance matching devices - prevents loss of intensity as sound travels from air to fluid

middle ear

combination of both conductive and sensorineural loss - middle and inner ear are not functioning properly

mixed loss

collects high frequencies, increases sound pressure to EAM, contributes to localization and binaural stim

pinna (auricle)

The movement of the hair cells generates ____ ___

nerve impulses

permanent damage to cochlear hair cells is caused by prolonged exposure to loud ______ or short exposure to extreme _____

noise

pressure of the waves causes movement in the hair cells in the _______________

organ of corti

The eardrum is connected to the malleus, which moves the ____ back and forth

ossicles

ratio of malleus to incus length increase sound pressure slightly

ossicles

funnels sound to the ear canal and helps localize sound

pinna (auricle)

2 parts of the outer ear

pinna (auricle) and external auditory canal

three small bones in the middle ears

ossicular chain

middle ear infection

otitis media

formation of spongy bone that fixates the footplate of the stapes on the oval window

otosclerosis

postnatal causes of SHL

ototoxic drugs that damage the ear mycin family infectious disease

three main parts of the ear

outer ear middle ear inner ear

As the Stapes moves, it pushes the ____ _______ in and out

oval window

part where the inner ear begins the oval window allows communication between scala vestibuli and middle ear spaces

oval window

negatively charged fluid

perilymph

2 types of inner ear fluids

perilymph endolymph

stapes is surgically removed and replaced with a prosthesis

stapendectomy

with otosclerosis, the stapes is often aggravated during ____, making them think it might be linked to hormones

pregnancy

hearing loss associated with normal aging progression from high to low frequencies

presbycusis

function of the outer ear

protection

use selected frequencies air conduction determine a hearing threshold

pure tone audiometry

allows communication between scala tympani and middle ear

round window

bone conduction and air conduction thresholds are essentially the ____

same

noise can cause what kind of hearing loss?

sensorineural

problem with the inner ear, auditory nerves, or brainstem damaged hair cells cannot be repaired - hearing loss is permanent

sensorineural loss

2 types of otitis media

serous and acute

fluid buildup; middle ear is inflamed and filled with thick or watery fluid

serous otitis media

whats the surgery for otitis media like

small incision in the tympanic membrane is made to relieve pressure

perilymph is composed of _____

sodium

Assists in localization ability and makes a contribution to frequency and intensity analysis

superior olivary complex

With sensorineural loss, they have difficulty hearing oneself and others so they tend to... and speech sounds are often...

talk louder difficult to understand

the primary auditory area in the brain is in what lobe?

temporal lobe

the Organ of Corti is ____ at the apex than at the base

thicker

the Organ of Corti is _____ at the base than at the apex

thinner

What makes up the vestibular system?

three semicircular canal

Two primary structures of the inner ear

three semicircular canals cochlea

intensity level at which a person hears the stimuli 50% of the time (Q)

threshold

various types of noise in the ear

tinnitus

people with central auditory hearing loss often complain about....

tinnitus trouble localizing sounds following complex instructions

With a blocked eustachian tube, the greater atmospheric pressure pushes the ________________ inward, reducing the mobility of the __________________, the _________________ does not vibrate properly and results in a conductive loss

tympanic membrane

eardrum thin, tough, elastic cone shaped membrane

tympanic membrane

the outer and middle ear are separated by the what?

tympanic membrane

SHL often goes _____ or ____ for months/years

undetected or misdiagnosed

what are the two branches of the acoustic nerve?

vestibular branch and acoustic branch

waves strike the eardrum causing it to _______

vibrate

The movement of the oval window makes ____ in the fluid in the cochlea

waves

Does Otosclerosis occur more frequently in men or women?

women

the eustachian tube can be opened by ___ and _____ (this lets fresh air into the middle ear)

yawning and swallowing