Three weeks after the surgery, the audiologist tested Lisa’s implant.
Animations that help us understand:
http://www.cochlear.co.uk/Experience/809.aspActual product Lisa has:
http://www.cochlear.co.uk/Products/447.asp"MAPping" is a term used by audiologists to describe how they have set the speech processor of a cochlear implant to provide sound to Lisa. Lisa went for her first MAPping appointment 4 weeks after surgery (Jan 10th). This is the first time that Lisa heard sound through the cochlear implant.
Lisa wears the device, and it is connected to the audiologist's computer. This tells the audiologist how the electrodes in Lisa's inner ear are working. Lisa 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, Lisa may not recognize it as the sound she should be responding to. The audiologist will watch Lisa'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.
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 Lisa to hear and to make sure it is never too loud.
The softest level for Lisa 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 Lisa. 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".
Lisa on 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 Lisa's MAP will be fine tuned and monitored for any changes.
Parents and therapists tell the audiologist how Lisa is hearing, to help the audiologist adjust Lisa's MAP. Some typical things to look for include Lisa complaining of sounds being too soft or too loud, unclear speech, and decreased listening distance for the softer sounds of speech.
When Lisa passes her first year with the cochlear implant, her MAP becomes relatively more stable. 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 Lisa can get used to the new sounds. New sounds usually have no meaning to Lisa at first. Lisa requires many experiences with sounds before they start to have meaning. There may not be many observable differences in Lisa after the first day of MAPping, but the new potential through hearing makes this an exciting moment for each family.
