Virginia Becar responded to our recent treatment of mother in which we claimed that ma was one of the first sounds made by a baby with this comment:
“My linguistics professor (from Harvard, no less) taught us that the first intelligable talk from babies is “da” not because they love daddy more, but because the tongue naturally goes to the top of the mouth in infants where they munch their food (the ripples are for pre-teeth stage of eating). The “ma” is a much harder sound to make since it involves nasal sound and comes later for that reason.”
Virginia’s professor was probably right, though the first sound a baby makes varies from baby to baby. Making an M sound is not that difficult for a child who hasn’t learned to control his or her velum (soft palate), which directs the flow of air through the pharynx to the nose. Making a nasal sound is a matter of simply leaving the pharynx open while closing the air passage through the mouth. One could just as well argue that da is more difficult because the baby has to close the opening to the pharynx in order to make the D sound.
Although I don’t recall any studies on the subject, my impression is that some babies do da-da-da, others ta-ta-ta, still others, ma-ma-ma first. I am sure that among the first sounds babies make is the ma-ma that gives us ma and that went into the making of mother.
By the way, if a baby just closes its lips and doesn’t open its pharynx or vibrate its vocal cords, the result is pa. This sound underlies the word for “father” in most Indo-European languages. It was pa-ter in Latin with the same kinship -ter that we find in mother, brother, and sister. In the Germanic languages, however, Proto-Indo-European P > F and T > TH regularly, which gave us father in English, exactly as expected.