Auditory System Flashcards
How does the auditory system transduce sound?
The vibration of air molecules stimulates hair cells of the auditory system
What parts of the waves make up each part of sound?
Amplitude = loudness Frequency = pitch Complexity = timbre
What are pure tones?
Do not naturally exist Sine wave Close relationship between tone and pitch Can't localize Generally uncomfortable
What are complex sound waves?
Sound in nature
What are neural tuning curves?
Tonotopic organization throughout the central auditory system
Each cell has a characteristic frequency to which it maximally responds
What happens in the outer ear?
The tympanic membrane vibrates and sends the vibration to the ossicle and the stapes triggers vibrations in the oval window
What is the cochlea?
Transfers vibrations to the endolymph of the cochlea
What is the organ of corti?
Composed of two membranes
-basilar membrane with the hair cells
-tectorial membrane which rests on hair cells
Deflection of organ of corti with sound shears the hair cells and stimulates them
How is the organ of corti stimulated by sound waves?
Higher frequencies act on hair cells by window
Lower frequencies act on hair cells by the tip of the basilar membrane
Different components of complex sound act in different locations
What is endolymph?
Fluid surrounding hair cells
Rich in potassium
-no need for Na+/K+ pumps
What are hair cells?
Sense movements in surrounding fluid
Cilia
Undergo mechanical stimulation which transduces into a neural impulse
What are outer hair cells?
3x more numerous than inner
Strong connection to tectorial membrane
Input from brain to ear
Cohlear amplifier
What is sound localization?
Sound originates on the ear that the noise is coming from
What is the auditory cortex?
Input from MGN Located in the temporal love within the lateral fissure Hierarchical A1 core, Heschl's gyrus -majority of input from mgn -tonotopic A2 -organized by frequency -Wernick'es
What is damage to the auditory cortex?
Rare
Lack of severe deficits
