Cochlear Implants Flashcards
What year did Cochlear Implants receive FDA approval?
1984
Who was the pioneer of CIs and responsible for the initial research? What is named for him?
Dr. William House
House Ear Institute
What are the 2 Main divisions of a Cochlear Implant?
Exterior (Speech Processor/Mic/Transmitter)
Interior “Internal Electronic Package” (Receiver/Electrode Array)
How many companies make Cochlear Implants?
What are they?
3;
Advanced Bionics Corporation
Chochlear Corporation
MedEl Corporation
What is a cochlear implant?
An advanced electronic device that is designed to provide functional hearing to individuals with severe to profound hearing loss
Where is the Internal Electronic Package implanted?
Implanted under skin, posterior to ear on the side of the head
T/F Cochlear Implant surgery is an outpatient surgery
T
Type of plastic that the human body does not reject; used in CIs
Cylastic
Where is the electrode array inserted?
Into the cochlea;
not all the way to the apex (won’t fit)
scala vestibuli
T/F All models of Cochlear Implants have different components.
F. All implants have the same basic components but differ in how the features are implemented.
What part of a CI does the speech coding?
External speech processor
What component decodes the signal from the speech processor? Where is it located?
The Receiver.
It is implanted beneath the skin.
What component converts the code to an electrical signal and stimulates nerve fibers in the cochlea?
Electrode Array
What does the receiver receive sound from? Where is it located?
The Transmitter (coil on the outside of Skin) It is held to the outside of the head, opposite the receiver, with a rare earth magnet.
What type of transmission does the Transmitter on a CI use?
FM
What is one limitation to CI users with respect to the transmitter magnet?
An implanted individual cannot have an MRI; it can dislodge and harm the CI and/or the user.
Low frequencies are processed at the apex and high frequencies are processed towards the base of the cochlea. Different frequencies have different “homes” along the cochlea.
Tonotopic Organization of the Cochlea
How does a Cochlear Implant work? (5)
- Sounds from environment captured by mic and sent to speech processor
- Signal is processed into distinct code
- Transmitter coil sends coded info as FM signal across the skin to the implant receiver
- Electrode array receives signal and stimulates nerve fibers
- Signal is delivered to the brain for interpretation
What must be intact in order for a CI to function?
Cochlear Connection to Auditory Nerve
What powers a Cochlear Implant? Where?
A battery inside of the speech processor. There is no battery implanted in the head.
What was the criteria for the first Cochlear Implant patients?
50% or less SRT
Progressive, acquired loss
Adults
By what age should children be implanted? Why?
Age 7. The brain will begin to re-assign synapses for processing, so it is imperative that a child begin to hear prior to that happening.
T/F: A cochlear implant amplifies the acoustic signal.
False. A cochlear implant directly stimulates the auditory nerve. There is no acoustic amplification.
Why don’t HAs help a patient who has extensive hair cell damage?
There is nothing to stimulate, even if the sound is amplified.
