Week 6 (How do we hear, taste, and smell?) Flashcards
What are the properties of sound
-Frequency & Pitch
-Amplitude & Loudness
-Complexity & Timbre
What is Frequency & Pitch
Rate of vibration n cycles per second (Hertz, Hz)
What is Amplitude & Loudness
Intensity of sound (Decibels, Db)
What is Complexity & Timbre
Complexity determines Timbre, (e.g. difference between violin and flute)
What are the three sections of the ear?
Outer ear, Middle ear, Inner ear
What are the components of the outer ear?
Pinnae: Funnel-like structure channels sound into ear.
Ear canal: Narrowing amplifies sound waves toward membrane (tympanic membrane)
What are the components of the middle ear?
Osssicles:
-Malleus (Hammer)
-Incus (Anvil)
Stapes (Stirrup)
What are the components of the inner ear?
Cochlea:
-Converts vibrational energy into waves of fluid
-The auditory part of the vestibulocochlear nerve
Inner ear includes vestibular apparatus.
Structure and function of the Cochlea
-Coiled structure, bony exterior, hollow compartments, filled with fluid.
-Vibrations from the ossicles to oval window membrane sends waves through fluid filled cochlea.
-Vibration is transmitted to organ of court via basilar membrane (structures in cochlea)
-Movement in sensory hair cells transduce sound waves into neural activity, which is sent along auditory nerve to the brain.
Structure and function of the tonotopic basilar membrane.
The basilar membrane vibrates when stapes moves the fluids of the inner ear. Different sound wave frequencies cause peak pending f the membrane at different points along its length.
What does the Organ of Corti
Sends vibrations to auditory nerve.
What is the auditory pathway to the brain?
-Ear (cochlea)
-Cochlear nuclei (brainstem)
-Superior olive (brainstem)
-Inferior Colliculi (midbrain)
-Medial geniculate nucleus (thalamus)
-Auditory cortex (Temporal cortex
Where are the primary and secondary auditory cortex located?
Primary:
Located in the temporal lobe, within the Heschl’s gyrus, within the Sylvia fissure, tonotopic.
Secondary:
-Surrounds primary auditory cortex,
What allows us to hear pitch
Tonotopic organisation in the basilar membrane.
What allows us to hear loudness
Louder sounds produce larger pressure changes, produces more intense basilar vibration.