Module 4 - Lesson 2 Flashcards
Hearing
Audition
The sense or act of hearing
Frequency
The number of complete wavelengths that pass a point at a given time (eg. per second)
Pitch
A tone’s apparent highness or lowness; dependent on frequency
Decibels
Used to measure sound
A sound has gone from 10 decibels to 30. What does this mean?
The intensity of the sound has increased by 200 times. Every 10 decibels corresponds to a tenfold increase in sound intensity, so 10 to 20 would be x10, and 10 to 30 would be x10x10, or x100
Middle Ear
Chamber between the eardrum and the cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window
Ossicles of the Ear
Malleus (hammer), incus (anvil), and stapes (stirrup). Connect the tympanic membrane to the inner ear
Cochlea
A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses
Inner Ear
Innermost part of the ear. Contains the cochlea, semicircular canals, and vestibular sacs.
What is the purpose of the oval window? Describe the movement of activity from the oval window to the auditory nerves.
When the oval window, the cochlea’s membrane, vibrates, it jostles the fluids inside the cochlea’s tube and causes ripples in the basilar membrane (this bends the hair cells and triggers nerve cells).
Basilar Membrane
A long coiled membrane inside of the cochlea that contains hair cells, which trigger auditory nerves.
What intensities can cause hearing loss with prolonged exposure?
Those that are 85 decibels and above
Hair cells can be _______ by prolonged exposure to loud noises.
Damaged
The brain interprets loudness from the ______ of activated hair cells.
Number
Compressed Sound
Quieter sounds are amplified, but louder sounds are not, creating a smaller range in volume.
Place Theory
Theory that links the pitch we hear with the place in the cochlea that is stimulated (high frequencies produce larger vibrations at the start of the membrane, low frequencies near the end).
Frequency Theory
Theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, which enables us to sense its pitch.
Compare place theory and frequency theory. Which better explains what (in terms of what sounds we can hear)? Why?
Frequency theory can explain why we hear lower pitched sounds, which have a lower frequency, but a single neuron cannot fire more than 1000 times per second, so how can we hear higher pitches?
Place theory can explain how we hear higher pitched sounds, but not lower pitched sounds because they are not so neatly localized on the basilar membrane.
Conduction Hearing Loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.
Sensorineural Hearing Loss
Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; also called nerve deafness. Can result from disease, but more commonly results from aging, heredity, and exposure to loud noises.
Cochlear Implant
A device that converts sounds into electrical signals. Stimulates the auditory nerve via electrodes threaded into the cochlea.
Describe the argument between hearing parents with deaf children and the Deaf community on cochlear implants.
The Deaf communities claims that because they can communicate without hearing, they do not have a disability and that children who are deaf prelingually should not be given hearing aids. Hearing parents who have deaf children want their children to be able to hear and speak. If these children were not able to get hearing aids before the age of consent, it may be too late for their brain to learn how to process auditory stimuli, and they will never hear.
