Babbling, often interpreted to mean the senseless gibberish uttered by hysterics
or the undifferentiated warbles produced by babies before they learn to speak,
means something quite different to speech scientists who study the acquisition
of speech in infants. For them babbling is a specific kind of sound: speech-like,
but non-linguistic (non-meaningful) strings of consonants and vowels uttered by
infants between the ages of seven months and approximately eighteen months.