You say that nerve deafness prevents transmission of the signal from the cochlea to the auditory nerve, and then say that the signal from the cochlear implant (more specifically the stimulator) relays the signal to the cochlea. But the problem, as stated, is transmission between cochlea and nerve. You see what I am saying? As you explain it, hearing loss will still persist.

My understanding of cochlear implants is that they are designed to overcome an issue in which the hairs within the cochlea are not able to transmit the action potential to the nerve axons that feed into the auditory nerve. The implant stimulator stretches into the cochlea and directly stimulates these nerves, removing the need for the hair cells to accomplish this part of the pathway. Since the stimulator can't reach all the way to the apex of the cochlea, and therefore can only directly stimulate some of the nerve axons that stretch into the auditory nerve, the sound that is generated from cochlear implants is not exactly the same as natural sound.

At 2:50, he says that the cochlea converts the electrical impulse from the stimulator into a nerve impulse. How does it do that?

Directly from Wikipedia (http://en.wikipedia.org/wiki/Cochlear_implant#Functionality): "The cochlear implant bypasses the hair cells and stimulates the cochlear nerves directly using electrical impulses. This allows the brain to interpret the frequency of sound as it would if the hair cells of the basilar membrane were functioning properly"

At 1:01, you said the individual has a problem with conduction. How does one determine it is a conduction issue as opposed to something else?

There is probably a very specific way that they would do it if you went to an ear doctor, but you can get a good idea of wether hearing loss is caused by conduction or if it is caused by other hearing loss by using a tuning fork. You can hit the tuning fork, and then place it on the very top of your head and listen to which ear it sounds loudest in. If you had something in your ear (blocking sound transmission) then this is the ear that the tuning fork would sound the loudest in. (you would have to double check this with something called the Rinne Test - http://en.wikipedia.org/wiki/Rinne_test : but that is where it becomes a little complicated)

To clear out...is it true that nerve deafness cannot convert from soundwave to electrical impulse rather than converting electrical impulse to neural impulse?

In a person with normal hearing ability, soundwaves are first converted into mechanical vibrations in the cochlear fluid. This causes movement of hair cells in the organ of corti. This in turn results in opening of K+ ion channels. Then there is opening of calcium ion channels. This represents conversion of soundwaves into electrical impulse. Later, these electrical impulses cause excitation of auditory nerve thus generating nerve impulse. In nerve deafness,there may be no opening of either potassium or calcium ion channels. thus, conversion may be hampered at either of the two stages.

how does microphone turn sound waves into electrical signal? (if u know any video explaining this please link, TQ)

By Faraday's Law of Induction. If you go to the Wikipedia page for 'Microphone' they explain the principles better than I could

He says sensory narrow hearing loss. Isn't it sensorineural hearing loss?

He says 'sensorineural' but you hear it as 'sensory narrow'.

Main content

Course: MCAT > Unit 10

Lesson 3: Sound (Audition)

Cochlear implants

Google Classroom

Cochlear implants restore some hearing to people with sensorineural hearing loss, or nerve deafness. Sound waves hit the microphone, converting them into electrical impulses. These impulses travel from the speech processor to the transmitter, then to the receiver implanted in the patient's skull. The stimulator sends this information into the cochlea, converting it into a neural impulse for the brain to process. Created by Ronald Sahyouni.

Want to join the conversation?

Sort by:

poulinn91
Posted 9 years ago. Direct link to poulinn91's post “You say that nerve deafne...”
You say that nerve deafness prevents transmission of the signal from the cochlea to the auditory nerve, and then say that the signal from the cochlear implant (more specifically the stimulator) relays the signal to the cochlea. But the problem, as stated, is transmission between cochlea and nerve. You see what I am saying? As you explain it, hearing loss will still persist.
Button navigates to signup pageButton navigates to signup page
(115 votes)
Answer
- meg uffen
  Posted 9 years ago. Direct link to meg uffen's post “My understanding of cochl...”
  My understanding of cochlear implants is that they are designed to overcome an issue in which the hairs within the cochlea are not able to transmit the action potential to the nerve axons that feed into the auditory nerve. The implant stimulator stretches into the cochlea and directly stimulates these nerves, removing the need for the hair cells to accomplish this part of the pathway. Since the stimulator can't reach all the way to the apex of the cochlea, and therefore can only directly stimulate some of the nerve axons that stretch into the auditory nerve, the sound that is generated from cochlear implants is not exactly the same as natural sound.
  Comment on meg uffen's post “My understanding of cochl...”
  (68 votes)
ss loves science
Posted 10 years ago. Direct link to ss loves science's post “At 2:50, he says that the...”
At
2:50
, he says that the cochlea converts the electrical impulse from the stimulator into a nerve impulse. How does it do that?
Button navigates to signup pageButton navigates to signup page
(10 votes)
Answer
- susa5
  Posted 9 years ago. Direct link to susa5's post “Directly from Wikipedia (...”
  Directly from Wikipedia (http://en.wikipedia.org/wiki/Cochlear_implant#Functionality):
  "The cochlear implant bypasses the hair cells and stimulates the cochlear nerves directly using electrical impulses. This allows the brain to interpret the frequency of sound as it would if the hair cells of the basilar membrane were functioning properly"
  Comment on susa5's post “Directly from Wikipedia (...”
  (19 votes)
Toni McDougall
Posted 9 years ago. Direct link to Toni McDougall's post “If the deficit is the neu...”
If the deficit is the neuronal transmission to the brain, then how does the transplant assist this deficit? The transplant still leads up to the same issue: the neuronal impulse not being delivered to the brain., because if something is wrong with the person's nerves, then the transplant can't help the issue because the transplant stops at the middle ear when the issue is with the inner ear
Button navigates to signup pageComment on Toni McDougall's post “If the deficit is the neu...”
(8 votes)
Answer
Jerry J. Français II
Posted 10 years ago. Direct link to Jerry J. Français II's post “At 1:01, you said the ind...”
At
1:01
, you said the individual has a problem with conduction. How does one determine it is a conduction issue as opposed to something else?
Button navigates to signup pageButton navigates to signup page
(4 votes)
Answer
- Nahn
  Posted 10 years ago. Direct link to Nahn's post “There is probably a very ...”
  There is probably a very specific way that they would do it if you went to an ear doctor, but you can get a good idea of wether hearing loss is caused by conduction or if it is caused by other hearing loss by using a tuning fork. You can hit the tuning fork, and then place it on the very top of your head and listen to which ear it sounds loudest in. If you had something in your ear (blocking sound transmission) then this is the ear that the tuning fork would sound the loudest in. (you would have to double check this with something called the Rinne Test - http://en.wikipedia.org/wiki/Rinne_test : but that is where it becomes a little complicated)
  Comment on Nahn's post “There is probably a very ...”
  (6 votes)
Jousboxx
Posted 9 years ago. Direct link to Jousboxx's post “What is the piece that is...”
What is the piece that is on top of the hole into the ear and connected to the speech processor? He never mentioned that part in the video.
Button navigates to signup pageButton navigates to signup page
(5 votes)
Answer
- avery
  Posted 5 years ago. Direct link to avery's post “It is called a T-Mic, and...”
  It is called a T-Mic, and it receives the sound waves, and sends it to the processor to process
  Button navigates to signup page
  (1 vote)
cpopo9106
Posted 7 years ago. Direct link to cpopo9106's post “How come the neural impul...”
How come the neural impulse goes to the cochlea, isn't the neurons there defective?
Button navigates to signup pageButton navigates to signup page
(4 votes)
Answer
coloremotion
Posted 9 years ago. Direct link to coloremotion's post “To clear out...is it true...”
To clear out...is it true that nerve deafness cannot convert from soundwave to electrical impulse rather than converting electrical impulse to neural impulse?
Button navigates to signup pageButton navigates to signup page
(1 vote)
Answer
- ss loves science
  Posted 9 years ago. Direct link to ss loves science's post “In a person with normal h...”
  In a person with normal hearing ability, soundwaves are first converted into mechanical vibrations in the cochlear fluid. This causes movement of hair cells in the organ of corti. This in turn results in opening of K+ ion channels. Then there is opening of calcium ion channels. This represents conversion of soundwaves into electrical impulse.
  Later, these electrical impulses cause excitation of auditory nerve thus generating nerve impulse.
  In nerve deafness,there may be no opening of either potassium or calcium ion channels. thus, conversion may be hampered at either of the two stages.
  Button navigates to signup page
  (3 votes)
Ci Qian W
Posted 9 years ago. Direct link to Ci Qian W's post “how does microphone turn ...”
how does microphone turn sound waves into electrical signal? (if u know any video explaining this please link, TQ)
Button navigates to signup pageButton navigates to signup page
(0 votes)
Answer
- Taylor Logan
  Posted 9 years ago. Direct link to Taylor Logan's post “By Faraday's Law of Induc...”
  By Faraday's Law of Induction. If you go to the Wikipedia page for 'Microphone' they explain the principles better than I could
  Button navigates to signup page
  (5 votes)
alizabhamani
Posted 9 years ago. Direct link to alizabhamani's post “He says sensory narrow he...”
He says sensory narrow hearing loss. Isn't it sensorineural hearing loss?
Button navigates to signup pageButton navigates to signup page
(0 votes)
Answer
- SUKANNYA
  Posted 8 years ago. Direct link to SUKANNYA's post “He says 'sensorineural' b...”
  He says 'sensorineural' but you hear it as 'sensory narrow'.
  Button navigates to signup page
  (4 votes)
Danny
Posted 7 years ago. Direct link to Danny's post “if the device has its own...”
if the device has its own microphone what is the bit in the patients ear?
Button navigates to signup pageComment on Danny's post “if the device has its own...”
(1 vote)
Answer

Video transcript

In this video, we're gonna talk about cochlear implants. Now, cochlear implants are basically a surgical procedure that attempts to restore some degree of hearing, of the ability to hear, to individuals that have something known as sensorineural hearing loss. And this is otherwise known as nerve deafness. So let's talk about sensorineural hearing loss real quick. So normally what we have is, we have sound waves coming in, they hit the ear. And then they travel through this auditory canal, cause the eardrum to vibrate back and forth, and this vibration causes these three little bones in the middle ear to vibrate back and forth. And eventually, fluid moves back and forth in the cochlea, and that fluid movement gets, stimulates hair cells that then produce an electrical signal that gets sent to the brain. Now individuals with sensorineural hearing loss, this conversion over here basically does not work. So there's a problem with conduction. And this can be surgically treated with something known as a cochlear implant. You know what, let me just write that down, so, "Cochlear implant." So let's talk about a cochlear implant. Let's just look at the different components of the cochlear implant. So, this implant part, which is what I'm highlighting right here, is known as a receiver. And then from the receiver extends this long kind of tube that goes all the way into the cochlea and turns around like that, and this tube is known as a stimulator. Now, what is the receiver doing? It's receiving information from this wall structure right here, and this is known as a transmitter. So the transmitter. And the transmitter is getting electrical information from this thing that I'm highlighting now, which is known as a speech processor. Speech processor. The speech processor basically gets information through this little opening, which is the microphone. So as sound waves come in, they hit the microphone, and the microphone takes the sound waves, converts them into an electrical impulse, which then gets sent to the transmitter, which you can see it some, it's outside of the individual's skull. And the transmitter sends that information to the receiver, which is inside, it's implanted inside the patient's skull. Then the receiver sends the information through the stimulator, into the cochlea, and then the cochlea converts that electrical impulse into a neural impulse that goes down the auditory nerve into the brain in order for that sound wave to be processed. And so basically, this effectively restores some degree of hearing to individuals with nerve deafness.