What happened to the child in Frederick Ⅱ’s experiment?

Is language a basic human need without which a child at a critical period of life can be starved and damaged? Judging from the experiment of Frederick II in the 13th century it may be. Hoping to discover what language a child would speak if he heard no mother tongue, he told the nurses to keep silent. All the infants died before the first year.
    Today no such drastic deprivation exists. Nevertheless, some children are still backward in speaking. Most often the reason is that the mother is insensitive to the signals of the infant. There are critical times when children learn more readily. If these sensitive periods are neglected and the ideal time for acquiring skills passes, they might never be learned so easily again.
    Linguists suggest that speech milestones are reached in a fixed sequence and at a constant age. At twelve weeks a baby smiles and utters vowel-like sounds; at twelve months he can speak simple words and understand simple commands; at eighteen months he has a vocabulary of three to fifty words. At three he knows about 1,000 words which he can put into sentences, and at four his language differs from that of his parents in style rather than grammar.
    Recent evidence suggests that an infant is born with the capacity to speak. What is special about Man’s brain is the complex system which enables a child to connect the sight and feel of, say, a teddy-bear with the sound pattern "teddy-bear". And even more incredible is the young brain’s ability to pick out an order in language from the hubbub of sound around him, to analyze, to combine and recombine the parts of a language in novel ways.
    But speech has to be triggered, and this depends on interaction between the mother and the child. Insensitivity of the mother dulls the interaction because the child gets discouraged and sends out only the obvious signals. Sensitivity to the child’s non-verbal cues is essential to the growth and development of language.