Motherese: The language spoken, all over the world, by mothers to their babies, before and after birth. Motherese is the earliest language a baby hears. A baby may be deprived of motherese through deafness or through separation from the parents.
"Reading about the seemingly miraculous, if controversial, technology of cochlear implantation, I came across the word motherese." (Fair D. BMJ 1998;316:753)