EAR NOTES/SOUND

SENSE ORGANS

• The sense organs gather information (light, sound, heat, and pressure) from the environment.

• Eyes, ears, nose, tongue, and skin are examples

HEARING

• When a sound is made, the air around the sound vibrates.

• Hearing starts when some of the sound waves go into the ear.

SOUND WAVES

• Sound is a series of waves that move through matter.

• Sound does not travel through a vacuum.

SOUND

• Sound moves at approximately 344 meters per second (770 miles per hour) at room temperature

• When a sound wave hits an object, it causes the object to vibrate. This leads to you to be able to detect sound.

SOUND WAVES

• Compression/Longitudinal waves: Sound travels in waves through the atmosphere.

• Sound can travel in transverse waves through solids.

3 MAIN PARTS OF THE EAR

• Outer Ear• Middle Ear• Inner Ear

SOUND WAVES TRAVELING THROUGH THE EAR

OUTER EAR

• The part that you can see.

• Directs sound into the ear

MIDDLE EAR• Ear canal: the tube between the outside of the ear and the ear drum.

• Ear drum: Vibrates when sound waves hit it.

MIDDLE EAR BONES

• The three smallest bones in the body are in the middle ear.• Hammer• Anvil• Stirrup

• Vibrations travel from ear drum -> Hammer -> Anvil -> Stirrup -> Inner ear

MIDDLE EAR

Ear Drum

Hammer

Anvil

Stirrup

INNER EAR

• Cochlea: fluid-filled organ in inner ear• Vibrations makes

waves, which send message to nerve

• Auditory nerve: carries the hearing information to the brain and the brain tells us what we heard.

Cochlea

THE EAR & BALANCE

• Semicircular Canals: fluid-filled canals in your ear that contain hair cells

• As you move, the hair moves from the liquid and sends messages to your brain about how you are moving.

Semi-circular Canals

HEARING LOSS

• Presbycusis: lose hearing as you age; runs in families; also caused due to extended exposure to loud noises

• Sudden Sensorineural Hearing Loss (SSHL): rapid loss of hearing; usually only one ear; more than 100 possible causes (disease, trauma, abnormal tissue growth, etc.)

• Noise-Induced Hearing Loss: caused by loud sounds, can be sudden (ex: explosion) or over time (ex: wood- shop)

HEARING LOSS

• Pendred syndrome: genetic disorder where early hearing loss occurs in children (by age 3)

• Meniere’s disease: a disorder of the inner ear that causes severe dizziness, ringing in the ears, hearing loss, and a feeling of fullness or congestion in the ear; usually affects only one ear; caused by build-up of fluid in the inner ear