Chapter 5: Sensation and Perception Part 2 Flashcards
sound waves
vibrations of the air in the frequency of hearing
auditory system converts:
sound waves into neural impulses
what are the two major qualities of sound waves?
frequency and amplitude
frequency
refers to the number of cycles the wave completes in a certain amount of time, measured in Hz (cycles/second)
amplitude
refers to the strength of a cycle, responsible for detection of “loudness,” measured in decibels (dB)
describe how sound waves are converted to neural impulses:
- sound waves enter ear and deflect tympanic membrane
- vibrations of tympanic membrane strike the ossicles (males, incus, and stapes). stapes hits oval window
- vibrations of the oval window create waves in the cochlea fluid, which deflects the basilar membrane. this movement bends the hair cells
- the hair cells communicate with the auditory nerve, which sends neural impulses to the brain
- signal travels to the brainstem, thalamus, and auditory cortex
- signal travels to auditory association areas in the cortex
tympanic membrane
the ear drum
ossicles
tiny bones in the ear called the malleus (hammer), incus (anvil), and stapes (stirrup)
oval window
a membrane separating the ossicles and the inner ear, deflection of which causes a wave to form in the cochlea
cochlea
fluid-filled structure in the inner ear; contains the hair cells
basilar membrane
structure in the cochlea where the hair cells are located
hair cells
sensory receptors that convert sound waves into neural impulses
tonotopic map
representation in the auditory cortex of different sound frequencies
brain is set up to integrate information from:
multiple sensory systems
frequency theory
different sound frequencies are converted into different rates of action potentials in our auditory nerves (high frequency=rapid firing)
place theory
differences in sound frequency activate different regions on the basilar membrane
regions along the basilar membrane send inputs to the brain that are encoded according to:
the place along the membrane where the inputs originated
low tones generally associate with:
frequency theory
high tones generally associate with:
place theory
absolute pitch
the ability to recognize or produce any note on a musical scale, associated with differences in brain anatomy
amusia
tone deafness, usually result of damage to the auditory system
list some ways in which sensory auditory systems can adapt:
- ears contract muscles around ear openings so less sound waves enter the ear when exposed to loud sounds
- hair cells of the ear become less sensitive to continuous noises
can sensory receptors of the auditory system by readily replaced?
no, damage can be permanent
cocktail party effect
brain files out sounds that are unimportant (even if it’s loud)