| Programming of the cochlear implant, or what is | | | | in several ways, depending the age or functioning level |
| commonly called a "Mapping", refers to the setting of | | | | of the patient. For children over age six, a hand raising |
| the electrical stimulation limits necessary for the | | | | method is used to determine T-Levels (similar to a |
| cochlear implant user to "hear" soft and comfortably | | | | hearing test). For children under three, a different |
| loud sound. Since the Cochlear Implant can only | | | | method is used, where the child is trained to look at a |
| process sounds in a very narrow range (6-15 dB), it | | | | moving toy in response to sound. The stimulation is |
| must be able to compress the natural range of sounds | | | | then reduced until the lowest level that the child is able |
| (normal speech is usually between 40-60 dB) into this | | | | to detect the sound. Typically, two audiologists are |
| small band. | | | | used; one training the child and one manipulating the |
| Due to the this small range of sound that a cochlear | | | | computer controls. |
| implant is limited to, CI users are more sensitive to | | | | For children between the ages of three and six, play |
| loudness changes. Therefore, "stimulation levels" must | | | | audiometery is used. The child is trained to place a |
| be set so the sounds processed by the cochlear | | | | block in a box in response to electrical stimulation. The |
| implant should not cause discomfort to the CI user. | | | | stimulation is reduced to the lowest detectable level. |
| These stimulation levels correspond to psychophysical | | | | Comfort level measurements may also be obtained in |
| (i.e. sensory responses to outside stimuli) | | | | several ways, depending the age or functioning level of |
| measurements known as Threshold (T) and Comfort | | | | the patient. For children over 5, a loudness scaling chart |
| (C or M) Levels. During the mapping process, the "T" | | | | or verbal response is used to determine Comfort |
| and "C" levels of each individual electrode on the | | | | Levels. For children under age five, the comfort levels |
| cochlear implant's internal electrode array (the spiral | | | | may have to be estimated, using the threshold levels |
| located inside the inner ear or "cochlea") are adjusted | | | | or other objective measures as a reference. |
| in order for the user to hear the wide range of sounds | | | | The mapping report provides printed out information on |
| that one is typically exposed to (soft to loud). | | | | map parameters, threshold and comfort level settings. |
| Threshold levels are set to allow the user access to | | | | Parents' understanding of this report is not necessary |
| soft speech and outside sounds. Comfort Levels | | | | in the child's progress with the device. It is merely a |
| refers to the amount of electrical current one needs | | | | print-out of the settings created during the mapping |
| for perception of a comfortably loud 'beeping' signal. | | | | session. It should be used only be used as a reference |
| These measurements are downloaded into the | | | | for the mapping audiologist. |
| speech processor, and then incorporated into a coding | | | | What may be helpful to the parent is a report of what |
| strategy, which the processor uses to send the | | | | is in each program slot. The parents should be given |
| electric signals to the internal implant in an organized | | | | instructions as to when or whether to change |
| manner. The processor will not allow the signals | | | | programs; which program may be designated for an |
| entering it to exceed these set measurements. | | | | FM System; which may be a back-up program or an |
| Each MAP is individual to its user and is constantly | | | | old program; which may be a noise program, etc. |
| changing. Over time, MAPs may become weak, softer, | | | | When a mapping is performed efficiently, the user will |
| or less clear. This may be the result of tissue growth, | | | | have hearing within a normal to near-normal hearing |
| or the user becoming used to their MAP and 'adapts' | | | | range. Parents may use the mapping sessions to |
| to it, finding that over time, it may no longer be a loud | | | | discuss progress at home, school, and in therapy. |
| enough signal. Re-programming the device will | | | | Questions and problem issues may also be addressed. |
| compensate for the changes that may occur due to | | | | The mapping audiologist will give recommendations on |
| adaptation. | | | | if and when to change programs as well as when a |
| Threshold (T-levels) measurements may be obtained | | | | follow-up appointment should be made. |