Cochlear Implants

• Cochlear Implant Surgery

Cochlear Implants

Cochlear implants are designed to help patients with profound hearing loss identify sounds. Cochlear implants are an electronic device that convert sounds into electrical impulses that can be sent to the auditory nerve. The auditory nerve processes sounds and sends the sounds to the brain. The cochlear implant surgery is completed as a day-operation and patients can return home after the implantation.

 

Difference Between Cochlear Implants And Hearing Aids

Cochlear implants are a complex electronic device different to a hearing aid. A hearing aid is used to enhance sounds. These enhanced sounds are sent into the ear in the same way as sounds naturally enter the ear; the sound passes through the outer an middle ear until it reaches the sensory receptor (hair cells) in the inner ear. 

 

Once the sound reaches the sensory receptors the sound is converted into electrical signals that are sent to the auditory nerve. The signals then pass from this nerve to the brain where the sound is recognized. 

 

Many of the problems triggering hearing loss are caused by damage to the sensory receptors. If the sensory receptors are damaged the sound is not translated into signals and the brain does not receive any sound.

 

Cochlear implants work by bypassing the damaged sensory receptors and replicating the function of the receptors to send electronic signals directly to the auditory nerve.  

How Do Cochlear Implants Work?

Cochlear implants are comprised of five parts:

• A microphone - this is placed on the outside of the ear and transmits sounds

• A speech/sound processor - this organizes the sounds transmitted by the microphone

• A transmitter - this receives signals from the speech processor and sends the 'sounds' to the receiver inside the ear via magnets.
  

• A receiver/stimulator  - placed inside the ear, the receiver converts these signals into electrical impulses. These impulses are then sent to the group of electrodes inside the ear, bypassing the damaged sensory receptors (this is similar to the way FM radio signals are transmitted).

• An electrode array - the electrical signals reach this group of electrodes inserted into the cochlear and send these impulses directly to the auditory nerve.  The auditory nerve then sends these signals to the brain.

The receiver/stimulator and group of electrodes are placed internally inside the ear. The transmitter, sound processor and microphone are worn outside of the ear and function as an advanced micro-computer. 

 

Success Of Cochlear Implants

Cochlear implants are an effective method of restoring hearing in profoundly hard-of hearing or deaf patients. Cochlear implants allow sounds to be heard in a different way to normal hearing. The sounds received are heard in a different way and often patients will be supported in learning to identify these sounds with a course of speech therapy.

 

Children who are born with a severe hearing impairment or are born deaf, adults who loose their hearing are good candidates for cochlear implants.

 

Adults who have previously relied on lip-reading and traditional hearing aids to process language and sounds may have difficulty adapting to the cochlear implants as the frequency of the sounds received differs to normal hearing. 

 

Deaf patients whose hearing impairment is caused by a problem with the auditory nerve will not benefit from cochlear implants.