About one to four weeks following surgery (depending on what type of incision your surgeon uses), the individual will return to the center for initial stimulation (or device activation) and orientation of all of the external equipment. The delay between surgery and initial stimulation is necessary to allow the incision to heal and any swelling to subside. It is important to note that the individual will not be able to hear with the implant or with a hearing aid in the implanted ear during this time.
The initial stimulation session, also called the initial “hook-up” or “activation”, involves fitting the individual with the external equipment (external transmitter coil/headpiece and speech processor) and programming of the device. After the ear surgeon has ensured that the surgery site has healed appropriately, the audiologist will select a magnet of appropriate strength to align the external transmitter coil with the implanted internal receiver. The audiologist will then connect the speech processor to the programming computer and will conduct a test that will verify appropriate internal device function. This brief test does not require participation from the recipient.
Next, the audiologist will create the initial program or “MAP” that will allow the individual to hear sound for the first time through his/her implant. The MAP contains information about how incoming sounds are converted to electrical stimulation levels. Each MAP is created specifically for the individual to ensure that soft sounds are audible, and that loud sounds are loud but never uncomfortable. To create a MAP, the audiologist activates the electrodes or electrode pairs and the recipient indicates the softest sounds he/she hears (threshold, or “T” levels) as well as the level at which sounds are louder, yet comfortable (most comfortable “M” levels, or comfortable loudness “C” levels). Once the speech processor program/s have been created, the processor microphone is activated so that the recipient will hear speech through the implant for the first time. It may be necessary to adjust additional parameters on an individual basis to enhance the quality of the sound derived from the cochlear implant.
After the final programs have been downloaded to the speech processor, the individual and his/her family are instructed on the operation, care, and maintenance of the device and accessories. Information regarding precautions, warranties, repairs, and insurance is also shared with those present. In addition, suggestions for incorporating listening practice at home may be given.