Hearing and balance Flashcards
The ear is divided into three areas
Outer, middle and inner
Outer ear includes:
External ear, outer canal, eardrum
What keeps air pressure in the middle ear to the ambient pressure
Eustachian tube. Its connected to the nasals, and it should not be blocked as it supposed to equalise the pressure
Middle ear
Airfilled, three small bones known as ossicles, converting pressure wave energy from eardrum to mechanical energy of motion
Inner ear
contains two pieces:
- Cochlea: for hearting. Converts mechanical energy from ossicles into electrical signals
- Vestibular appartus: (static organ and semi circular canals) Contain fluid and small hairs that convert gravity and acceleration orces into electrical signals
Human frequency hearing sound range
20Hz - 20kHz
Conductive hearing loss
Hearing loss which is primarily not caused by loud sounds or longs exposures, such as: ear wax, barotrauma, fluid problems in middleear, faulty ossicle
Sensory or noised-induced hearing loss
Loss of sensitity in hair cells in the cochlea, through exposure to noise, infection or age
Presbycusis hearing loss
Caused by age and especially in higher freq.
Where acceleration is detected in the body
Semi-circular canals in the inner ear for angular accelerations and static organ for gravity and linear accelerations
Spatial Disorientation
Not knowing your attitude in space
Vertigo
Feeling of rotation (which is false) caused by: disease, accelerations, sudden pressure changes
The “Leans”
the illusion the airplane is banked while its wings are leveled
When in a turn, whats the illusion
of climbing
Rolling back after a turn, whats the illusion
decsending
