How do you Hear?

• Your ears are the sense organs that respond to the stimulus of sound. The ears convert or change the sound to nerve impulses that your brain interprets.

How sound is produced

• Sound is produced by vibrations (moving rapidly back and forth)

• Ex. Guitar string, insect wings, splashing water

• Vibrations create waves. Waves move outward from the source of sound, like ripples moving out from a stone dropped in water

• Ex.

Air: Hearing your friend talk

Liquid: dolphins communicating

Solid: wood

Sound Vibrations and the Ear

• The ear is structured to receive sound vibrations.

Outer Ear

Ear Canal • Sound waves travel down this canal

Outer Ear

• Eardrum • Seperates the outer and middle ear. A membrane that vibrates when sound strikes it

Middle Ear

• Hammer • Vibrates from the eardrum and passes the vibration on to the anvil

Middle Ear

• Anvil • Vibrates from the hammer and passes the vibration on to the stirrup

• Stirrup• Vibrates against a

thin membrane covering the inner ear and sends the vibration into the fluid in the cochlea

Inner Ear

• Semicircular Canals • Structures in the ear that give you your sense of balance

Inner Ear

• cochlea • Snail-shaped tube lined with nerve cells that respond to sound when fluid vibrates, stimulates nerve cells

• Auditory Nerve • Sensory neurons send nerve impulses to the brain through the auditory nerve. These are interpreted as sounds that you hear

How You Hear

1. Sounds Waves2. Ear canal3. Eardrum4. Hammer5. Anvil6. Stirrup7. Cochlea8. Auditory Nerve9. Brain10.You hear the sound

• Ear Structure and Function

• Anatomy of the Ear

• Hearing

• Frequency

• Sound Transduction

• Effect of Sound Waves on Cochlear Structures