According to a new study published in the journal, Developmental Science, hesitant speech may help children learn new vocabulary words.  When a toddler hears a speaker using “um” or “uh” while speaking, the hesitancy serves a cue that a new word is coming next.  While the ability to use disfluencies as learning clues seems to develop over the second year of life, researchers are still curious to learn more about out what exactly children know and understand about the “ums” and “uhs” in speech. 

http://www.livescience.com/13719-speech-stumbles-teach-toddlers.html

This article explores the significance of babies’ babble, and how these first sounds and utterances lead to more advanced communication, including both receptive and productive language.  It appears that babies’ around the world babble in similar ways, and researchers are becoming increasingly interested in interpreting these sounds and the impact they have on both cognitive and social development.

http://www.nytimes.com/2010/10/12/health/12klass.html?_r=1