Hearing Flashcards
What is sound frequency measured in?
Hertz
What is sound volume measured in?
Decibels
What is the average human auditory range?
20-20,000 Hz
What is the organ of Corti?
Area of the ear containing vibration sensitive hair cells which are responsible for detecting sound
What is the function of the inner hair cells?
Detecting sound
What is the function of the outer hair cells?
Amplifying sound
How many rows are there of inner and outer hair cells in the ear?
1 row of inner hair cells
2 rows of outer hair cells
How are different sounds registered by the hair cells?
The hair cells have different tunings depending on their location.
What ion movements occur to cause depolarisation of the hair cells?
K+ ions move INTO the cell
What are spinal ganglion neurones?
The afferent neurones of the 8th cranial nerve
Where do the spinal ganglion neurones synapse?
95% to inner hair cells
5% to outer hair cells
How is a loud sound indicated to the brain?
Lots of action potentials in a larger number of axons
Describe the pathways of the sound impulse through the brain
Cochlea Spiral ganglion cells Cochlear nucleus Superior olivary complex Inferior colliculus Medial Geniculate Nucleus Auditory Cortex
Give 6 causes of hearing loss
Age Loud noise Congenital defects Infections Ototoxic compounds Trauma
Give 3 ways the ear can be assessed
Otoscope
Audiogram
Otoacoustic emissions
Auditory brainstem responce
