Transcript The Inner Ear – Structure and Function

The Inner Ear – Structure and
Function
By Mr. Bleecker and his Cat
Structure of the Ear
Outer Ear = Pinna
designed to gather and collect sound into the
ear canal
Middle Ear – the Auditory Canal
Channels the sound toward the EAR DRUM
Middle Ear – the Ear Drum is actually
called the “TYMPANIC MEMBRANE”
Sound waves = vibrations
HAMMER hits ANVIL moving the STIRRUP!
What Happens Next?
1. Sound waves travel into the SPIRALLED COCHLEA
2. Tiny hairs in the COCHLEA move to the beat, and send
impulses along nerve fibres
3. All nerve fibres link to the AUDITORY NERVE, to the
brain.
Inside the COCHLEA!
Eustacian Tube
Detectable Sound Levels – What can the Machinery Pick UP?
What Frequencies can we Hear?
2 000 - 20 000 Hz
100 000 – 140 000 Hz
Appearance of a Sound Wave
Detectable Sound Levels – What can be Heard?
Sound Wave Production
Soft (Low)
Levels of Intensity
Harsh(High)
Defeating Deafness – Cochlear Implants
•The implant generates
electric signals as the
sound bounces off
detector
•Vibrations = electricity
•Electricity stimulates the
AUDITORY NERVE
directly
Protect your Hearing!

Ear plugs
 Ear – muffs
 Keep the volume
down
Spidey knows the Value of Protecting Your Hearing!
Copy out these notes
1. Pinna
= outer portion of ear used to collect sound waves
2. Auditory Canal = tube that sound travels down
3. Ear Drum = membrane that sends sound waves to hammer
4. Hammer
= first of 3 bones. It vibrates, striking the anvil to carry on
the sound
5. Anvil
= gets hit by the hammer, striking the Stirrup
6. Stirrup
= vibrates against OVAL WINDOW, carrying on sound
7. Cochlea
= a spiral full of sensory “hairs,” which when bent, send
an electrical signal to the AUDITORY NERVE
8. Auditory Nerve = carries all signals for sound to brain
9. SemiCircular Canals = full of gel-like material. Indicates if you are
right side up or upside down. (Balance)