The Inner Ear – Structure and Function By Mr. Bleecker and his Cat

Structure of the Ear

designed to gather and collect sound into the ear canal 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? Sound waves travel into the SPIRALLED COCHLEA Tiny hairs in the COCHLEA move to the beat, and send impulses along nerve fibres 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 Levels of Intensity Soft (Low) 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 Pinna = outer portion of ear used to collect sound waves Auditory Canal = tube that sound travels down Ear Drum = membrane that sends sound waves to hammer Hammer = first of 3 bones. It vibrates, striking the anvil to carry on the sound Anvil = gets hit by the hammer, striking the Stirrup Stirrup = vibrates against OVAL WINDOW, carrying on sound Cochlea = a spiral full of sensory “hairs,” which when bent, send an electrical signal to the AUDITORY NERVE Auditory Nerve = carries all signals for sound to brain SemiCircular Canals = full of gel-like material. Indicates if you are right side up or upside down. (Balance)