From Listening to Speaking: The Missing Link
At around 18 months of age, a child's vocabulary and grasp of language suddenly expands, and scientists don't know why, states the Johns Hopkins University's publication, The Science Daily News Release, "One possible explanation is that children may begin storing the sounds and meanings of words while they are infants, and suddenly they are able to connect the words with meanings." This theory explains the speaking process as being similar to separate pieces of a jigsaw puzzle suddenly fitting together.
Experimental psychologists at Johns Hopkins found that eight-month-old babies recognized relatively complex words, even when they'd only heard those words in tape-recorded stories.
According to Dr. Peter Jusczyk, PhD, a professor in the Department of Psychology at Johns Hopkins University, infants have a keen memory for learning words. "What we found was that the babies listened longer to the lists of words from stories (that they'd heard previously); significantly longer," Dr. Jusczyk reports.
Another study conducted on babies less than one week old by 11 Finnish scientists and Dr. Amir Raz, a fellow of psychology and psychiatry at the Sackler Institute for Development Psychobiology of Weill Cornell Medical College, led to more interesting results. They found that, unlike the anecdotal study-while-you-sleep approach for adults, newborn babies can and do learn to distinguish speech sounds while asleep, though it remains to be seen up to what age children retain this ability to learn while asleep.
The question this raises for us as parents is: If these conclusions were drawn using controlled, testing environments, how much more likely is a baby to learn and flourish when actually held and cuddled in a parent's arms while turning the pages of a book? Or while perching on a mother's shoulder watching her work close-up? Wouldn't it be reasonable to conclude that the more words an infant is exposed to throughout babyhood, the more words she's likely to retain and, consequently, the earlier she's likely to speak?