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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.
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
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