Sentence:  The auto-imitation in <WSD>lallation</WSD>, a form of spontaneous talking, precedes the imitation of strange words and sounds. ... in <WSD>lallation</WSD> the infant follows his own inclination, while in imitating the sound heard from others he will have to accommodate himself to a strange perception. 
Meaning of the word marked with <WSD> tags:  Baby-talk or gibberish.