The Auditory System Flashcards
What is sound?
Sound is a series of pressure change in air that can vary in frequencies and intensities.
What do we experience frequencies and intensities as?
Frequencies - pitch or tone
Intensities - loudness or volume
Where do sound waves bounce off of in our ears?
They bounce off of the folds of our ears and travel down the auditory canal where they vibrate in the ear drum.
What happens with the vibrations in the ear drum?
They are changed from pressure waves to physical movements in the middle ear. These movements are transferred through the middle ear using the tiniest bones (in the human body).
What are these tiny bones in the middle ear called?
The ossicles.
When sick, what can happen to the middle ear?
The middle ear is filled with air so when sick, it become congested and the eustachian tube will narrow.
What is the eustachian tube?
This tube connects the middle ear to the back of the throat.
What are the three ossicles in the middle ear?
The malleus, the incus, and the stapes.
What do the three ossicles in the middle ear do?
They work together to transfer physical movement of the vibrations of the eardrum through the middle ear to the fluid of the inner ear.
How do the three ossicles work in the middle ear?
It’s easy to move fluid with air so the ossicle is like a lever which increases the pressure to move the fluid of the inner ear.
What are the two sections in the inner ear?
The cochlea and the semicircular canals.
What does the cochlea do?
This is where sound is changed into nerve messages and sends them to your brain.
What do the semicircular canals do?
This is for converting the movements of the head.
How does the cochlea work?
This is filled with liquid that ripples with the ossicles beat against it. The stapes beats against the exposed flexible membrane called the oval window. This creates waves. There are nerve endings (hair cells) that transform the vibrations into electrical impulses which go to the brain.
What happens in the Organ of Corti and where is it?
The Organ Corti is in the Cochlea and this is where the translation of pressure waves through the fluid into an electrochemical signal.
