Turning the implant on
Receiving the equipment
3 weeks (after surgery) - Equipment appointment
Three weeks after the surgery, the audiologist will give your child the external device (speech processor and coil). Depending on your child's age and other factors, there are two different processors that may be provided. For younger children, a body processor is given. The external device looks like this:
The microphone is in the middle of the picture (it looks similar to a hearing aid). The transmitting coil is the circular piece to the left of the microphone and the speech processor is to the right.
If the incision from your child's surgery has healed, your child will begin to wear the device for 1 week before the switch on. This way, your child can get comfortable with the device. The device is not turned on at this time.
For older children, an ear-level processor may be provided. The provision of an ear-level device depends on specific factors that will be determined by the Cochlear Implant Program. The ear-level processor looks like this:
The microphone and the speech processor are combined into one unit that fits behind your child's ear. The transmitting coil is to the left of the microphone/processor.
Older children may not need a week to adjust to their equipment and may instead receive the equipment on the same day the implant is activated.
The first day of MAPping - "switching on" the cochlear implant
4 weeks (after surgery) - Switch-on #1
"MAPping" is a term used by audiologists to describe how they have set the speech processor of a cochlear implant to provide sound to the child. Typically, a child comes for his/her first MAPping appointment 4 weeks after surgery (1 week after receiving the equipment). This is the first time that your child will hear sound through the cochlear implant.
Since most parents are nervous on the first day of MAPping, the audiologist will suggest that only parents (not other family members) come with their child. We can videotape the session for parents who would like us to do so.
Turning on the device
Your child wears the device, and it is connected to the audiologist's computer. This tells the audiologist how the electrodes in your child's inner ear are working. Your child and the audiologist now work together to set the sound levels presented to each electrode within the cochlea (inner ear).
Even children who have had a lot of experience with sound may have trouble at the beginning of this first MAPping. Because the sound/sensation may be so new, your child may not recognize it as the sound he or she should be responding to. The audiologist will watch your child's face to see if the signal is being heard. Some signals might be quieting, focusing their eyes, tensing their brow, needing a hug from mom.
Adjusting the sound levels
Imagine the internal part of the cochlear implant as a coil with a string of electrodes. In fact, it is sort of like an electric organ keyboard. The audiologist has to set each electrode to play a particular note loud enough for your child to hear and to make sure it is never too loud.
The softest level for your child to hear is called the T level (threshold level) and the upper level is the C level (comfort level). The T and C levels are different for each child. The audiologist sets these levels over several sessions. The way that a particular speech processor is set for a particular child is called his/her "MAP".
A child on his/her first day of MAPping may not yet be used to hearing, and T levels will likely change over the first few sessions. The new sound may also be overwhelming and C levels may be reduced and increased gradually over the first few sessions. Over the first year your child's MAP will be fine tuned and monitored for any changes.
Parents and therapists tell the audiologist how the child is hearing, to help the audiologist adjust the child's MAP. Some typical things to look for include your child complaining of sounds being too soft or too loud, unclear speech, and decreased listening distance for the softer sounds of speech.
When your child passes his or her first year with the cochlear implant, his or her MAP becomes relatively more stable. At our Program, children usually only return every 6 months for a MAP, after they have had the implant for one year.
The first day of MAPping is sometimes not as exciting as anticipated. This first MAP may be conservative so that your child can get used to the new sounds. New sounds usually have no meaning to your child at first. Your child requires many experiences with sounds before they start to have meaning. There may not be many observable differences in your child after the first day of MAPping, but the new potential through hearing makes this an exciting moment for each family.