Section 3 Fundamentals

Anvil

(The incus) a small anvil shaped bone in the middle ear that transmits vibrations between the hammer and stirrups

Hammer

(The malleus) a small bone in the middle ear, that transmits vibrations of the eardrum to the anvil

Stirrup

(The stapes) a small stirrup shape bone in the middle ear that transmits vibrations from in incus to the inner ear

The outer ear includes:

1.Auricle: cartilage covered by skin placed on opposite sides of the head 2.Auditory canal (the ear canal) 3.Eardrum outer layer (tympanic membrane) The outer part of the ear collects sound Sound travels through the auricle and the auditory canal, a short tube that ends at the eardrum

The inner ear includes:

1.Oval window 2.Semicircular ducts 3.Cochlea 4.Auditory tube When the stapes moves, it pushes the oval window, which then moves the cochlea The cochlea takes the fluid vibration of sounds from the surrounding semicircular ducts and translates them into signals that are sent to the brain by nerves like the vestibular nerve and cochlear nerve

What are the three different functions that the ear is made up of?

1.The outer ear 2.The middle ear 3.The inner ear These parts work together so you can hear and process sounds

Types of hearing loss

1.conductive hearing loss 2.sensory hearing loss 3.mixed hearing loss 4.central hearing loss

The middle ear includes:

1.eardrum 2.cavity (the tympanic cavity) 3.ossicles (3 tiny bones that are attached) Malleus Incus Stapes Sound entering the outer ear travels through the middle ear and causes the eardrum and ossicles in the middle ear to vibrate As it travels, it amplifies and changes from air to liquid

Other problems can happen later because of an injury or illness, including:

1.middle ear fluid 2.serious infections, such as meningitis 3.head injury 4.listening to very loud music, especially through headphones or ear buds 5.repeated exposure to loud sounds, such as machinery

Hearing levels are often described in a progression of loss:

1.normal hearing (0-20 dB) 2.mild hearing loss (21-40 dB) 3.moderate hearing loss (41-55 dB) 4.moderately severe hearing loss (56-70 dB) 5.Severe hearing loss (71-90 dB) 6.profound hearing loss (>90 db)

Mixed hearing loss

A combination of conductive and sensory, meaning there's damage in all parts of the ear

Hearing

A complex sense involving both ears ability to detect sounds and the brains ability to interpret those sounds, including the sounds of speech

Audiograms

A graph that shows the audible threshold for standardized frequency as measured by an audiometer

Rinne test

A hearing test that evaluated hearing lost in one ear and compares perceptions of sound transmitted my air circulation, to thoughts transmitted by bone conduction.

Tympanic membrane

A membrane forming part of the organ of hearing which vibrates in response to sound waves

Central hearing loss

A result from defects in the central nervous system, rather then the ear itself.

Tympanic cavity

A small cavity surrounding the bones of the middle ear

Conductive hearing loss

Caused by damage to the wave carrying portions of the ear

How is hearing loss treated?

Common treatments include: 1.medicine 2.operations 3.hearing aids 4.other assistive listening devices 5.air conduction 6.audiograms 7.cochlear implant 8.Rinne test 9.speech in noise test

Oval window

Connects the middle ear with the inner ear

When the tympanic membrane vibrates and

Converts sound to mechanical waves, it causes the ossicles (earbones) to vibrate

Sensory hearing loss

Damages to the hair cells in the cochlea

The human ears are designed to...

Detect sounds in a set range of pitches and frequencies. Detecting this sound involves the ear.

Auditory tube

Drains fluid from the middle ear into the throat behind the nose

Ossicles

Earbones

Tympanic membrane

Eardrum

Cochlear implant

Electronic medical device that replaces the function of the damaged inner ear and provides cell signals to the brain

Semicircular ducts

Filled with fluid, attached to cochlea and nerves, send information on balance and head position to the brain

What causes hearing loss?

Hearing loss can happen because a person was born with parts of the ear that didn't form correctly and don't work well

The stapes

Hits the oval window as it vibrates, pushing on the fluid inside the cochlea to vibrate in the form of fluid wave. This vibration travels through the cochlea, stimulating the sensory hair cells, which are incredibly sensitive. Their stimulation results in a signal passing to the cochleae nerve, which sends a signal to the brain so sounds can be interpreted.

Pitch is caused by...

How close together waves are (frequency) which intensity is determined by how tall the waves are (amplitude)

Amplitude

How high the sound waves are, which is what we perceive as loudness

Meningitis

Inflammation of the brain and spinal cord, typically caused by an infection

Characteristics of hearing loss

It can impair a person's ability to communicate effectively It is caused by aging, disease, heredity, and noise It affects millions of Americans

Facts about sound

It cannot travel through a vacuum It must travel through something- air, water, or even bone Major aspects of sound: 1.amplitude 2.frequency 3.intensity (loudness) Both amplitude and frequency deal with the waves that sound produces

Auditory canal

It extends from the pinna to the eardrum

Air conduction

It occurs through air near the ear

Malleus (hammer)

Long handle attached to the eardrum

Eustacian tube

Maintains pressure within the inside and outside of the ear. If pressure is different, sound doesn't travel right!

Intensity

Measured in decibels dB

The outer ear, or...

Pinna (auricle) (The part you can see Picks up sound waves and the waves then travel through the outer ear canal

The process of sound

Sound is collected in the outer shell of the ear. (Pinna). This sound travels in air through the auditory canal until it reaches the tympanic membrane (eardrum). Sound causes the tympanic membrane to vibrate.

Cochlea

Spiral-shaped organ of hearing, transforms sound into signals that get sent to the brain

Incus (anvil)

The bridge bone between the malleus and the stapes

When the sound waves hit the eardrum in the middle ear...

The eardrum starts to vibrate, when the eardrum vibrates, it moves three tiny bones in your ear. These bones are called the hammer, anvil, and stirrups. They help sound move along on its journey into the inner ear.

Stapes (stirrup)

The footplate, the smallest bone in the body

The malleus vibrates, causing...

The incus to vibrate, causing the stapes to vibrate

Vesicule

The middle part of the inner ear that is involved in maintaining balance. A set of three tubes that give you the ability to sense up, down, and sideways.

Frequency

The number of sound waves that cross a point in a certain amount of time

What are the two types of hair cells?

The outer and inner cells The sound vibrations make the tiny hairs move. The outer hair cells take the sound information, amplify it, and tune it. The inner hair cells send the sound information to your hearing nerve, which then sends it it your brain, allowing you to hear.

Cochlea

The spiral cavity of the inner ear containing the organ of Cort, which produces never the impulses in response to sound vibrations The vibrations travel to the cochlea, which is filled with liquid and lined with cells that have thousands of tiny hairs on their surfaces.

The role of balance and the human ear involves...

The vestibule of the ear, which houses the semicircular canals

Speech in Noise test

This ensures a person ability to hear speech in silence and in noise