What is a Cochlear Implant?
Understanding Cochlear Implants: Function, Components, and Operation
A cochlear implant is a small electronic device, similar to a pacemaker, which helps restore hearing function for those who have severe to profound hearing loss. This device is surgically implanted underneath the scalp and a small electrode is threaded into the inner ear so that electrical impulses can stimulate hearing.
Through the implant, sound is converted from acoustic energy into electrical energy. Normally, sound travels through three separate compartments of the ear: the outer ear, the middle ear, and the inner ear. A cochlear implant bypasses the outer ear and the middle ear to cause direct stimulation on the inner ear and transmission of this information to the brain.
A cochlear implant has 2 components: An internal device (the implant) and the external device (the processor). There is current research aimed at creating a completely implantable cochlear implant, which will not require an external processor.
The 4 most important parts of the cochlear implant are:
- Microphone (External)
- Speech Processor (External)
- Receiver/Stimulator (Internal)
- Electrodes (Internal)
This device works by picking up sound through the microphone and sending it through the speech processor, which works to convert the sound into electrical signals. Once these signals are relayed to the transmitter, the information is passed through the electrode to stimulate the hearing nerve inside the cochlea (a.k.a Organ of Hearing).
Who is the best candidate for a Cochlear Implant?
Patients who have a history of severe to profound hearing loss and have no benefit from hearing aids are good candidates for cochlear implants. The surgery can be performed on infants born with hearing loss or adults who develop hearing loss over the years.
A trained otologist (ear surgeon) can usually examine the patient and review an audiogram (hearing test) to be able to assess if someone may be a candidate for a cochlear implant. To further ensure candidacy, a comprehensive audiological evaluation will be ordered and a CT scan of the ear will be performed.
What is the recovery process after a Cochlear Implant procedure?
A cochlear implant is an outpatient procedure that usually takes less than 2 hours to perform. In our center, the patient is discharged the same day, and is able to do some work from home on the 2nd day after surgery.
There is minimal pain with the procedure, and pain meds are given just in case. Most patients can usually return to completely normal activity about 1 week after surgery. The cochlear implant is usually activated about 1 month after the initial implantation of the device.
What does it sound like with a cochlear implant?
Upon activation of the implant, most patients describe the speech they hear as “robotic” or “like Mickey Mouse”. This type of sound quality shortly improves and the patients begin to hear speech more naturally.
The first month of rehabilitation is dedicated to make sure the sounds are recognizable and comfortable. The following months are geared toward understanding and re-learning speech discrimination.
There is usually improvement every week, and with a lot of practice, most patients exhibit satisfactory speech understanding at 3 months after activation. Generally, hearing tends to improve with more experience utilizing the device. By 6 months to 1 year, most patients can function very well and enjoy the full potential of the implant.
