THE HEARING BRAIN Flashcards
Sound waves: What are they, physical and perceptual properties
(general)
The Auditory Stimulus: airborne sound waves
Traveling vibrations of air that alternate between compression (squeezing) and rarefaction (stretched apart) of air molecules
Sound waves have different physical qualities which are approximately related to how we perceive the sound
frequency is :
measured in ___
Physical quality ____
perceptual quality ____
physical qualities which are approximately related to how we perceive the sound
Amplitude
measured in ___
Physical quality ____
perceptual quality ____
physical qualities which are approximately related to how we perceive the sound
overtones
measured in ___
Physical quality ____
perceptual quality ____
physical qualities which are approximately related to how we perceive the sound
basic pathway - sensation to perception
Receptors transduce the physical signal into a neural signal
• Before the receptors:
▫ Outer ear (pinna), auditory canal ▫ Middle ear (eardrum, ossicles)
• Outer and middle ears funnel signal into the inner ear
• Receptors are in the inner ear
▫ Hair cells located in the cochlea
Sensation: stimulus affects a receptor
• Receptor transduces the stimulus: turns a
physical stimulus into a neural signal
Perception:
interpretation of sensations to create a model of the world
Outer ear
Pinna captures sound waves and funnels them inward
• amplifies certain frequencies: important for locating sounds
Middle ear
Ossicles (malus incus and stapes)
tympanic membrane = ear drum
Inner ear
COCHLEA —
Auditory nerve
Transduction in the cochlea
Pressure waves in fluid of cochlea cause basilar
membrane to move up and down
• Movement affects hair cells in the organ of Corti
▫ Movement causes the hair cells to fire action potentials
▫ Hair cells are thus the receptors for sound.
(Movement of the basilar membrane shifts the tectorial
membrane, which moves the sterocilia) = causes neurons to fire