Hearing Flashcards
What is audition?
-the sense of hearing
What is the stimulus for a sound?
-a wave of pressure created when an object vibrates (or when compressed air releases)
What happens when a wave of pressure is created?
-molecules in a transmitting substance move together and apart
Define: the transmitting substances of pressure waves
-air, water, or solids
What are the 3 psychological dimensions of auditory experience?
- loudness
- pitch
- timbre
Define: loudness (psychological dimension of auditory experience)
- related to intensity of pressure wave
- corresponds to wave amplitude
- measured in decibels
What is the average absolute threshold of hearing?
-0 decibels
Explain: how decibels are not equidistant
-every 10 decibels, there is a tenfold increase in sound intensity
Define: Pitch (psychological dimension of auditory experience)
-related to frequency of pressure wave
-number of times the wave cycles through a peak and low point per second
- measured in hertz (Hz)
(1 cycle/second is 1 hertz (Hz))
Define: timbre (psychological dimension of auditory experience)
-the distinguishing quality of sound
-related to complexity of pressure wave
-the breadth of range of frequencies that make up the wave
(a single frequency of sound is extremely rare in nature)
Define: white noise
-when all the frequencies of the sound spectrum occur simultaneously
What sections are the ear divided into?
- outer section
- middle section
- inner section
What is the function of the outer ear? (the soft funnel-shape we can see)
-designed to collect sound waves, but our hearing would still be good without it
What is the actual organ of hearing?
-organ of Corti
Where is the organ of Corti located?
-inside the cochlea
What are the receptor cells for hearing, that are inside the organ of Corti?
-bristle-like (hair cells), topped by tiny bristles, (clia)
Brief exposure to extremely loud noises, or prolonged exposure to moderate noises can damage the hair cells. Is hair cell damage curable?
-hair cell damage is currently irreversible
What rubbery material stretches across the interior of the cochlea, and embeds hair cells in place?
-basilar membrane
What does the basilar membrane do?
-waves of fluid, caused by pressure in the cochlea, push on the basilar membrane, causing it to move in a wave-like fashion also
There is another membrane ABOVE the hair cells. What is its purpose?
- basilar membrane movement causes hair cells to rise and fall. Their tips brush against this membrane and bend.
- this causes hair cells to initiate a signal that gets passed to the auditory nerve
What does the auditory nerve do?
-sends messages to the brain
What allows us to hear different sounds?
- the pattern of hair cell movement determines which neurons fire, how rapid they fire
- pattern of hair cell movement is affected by how the basilar membrane moves
(different frequencies lead to different neural codes)
How are high pitch and low pitch sounds discriminated?
high pitch
-where activity occurs on the basilar membrane
low pitch
-frequency of the basilar membranes’s vibration
what initiates nerve impulses for sound?
-hair cells
