I found this video the other day and was amazed by what this woman has discovered about infant communication. I very interested in her theories, so I listened very carefully to her explanations about how babies communicate with us. If you watch this, in particular pay attention to the "whys" of the babies' sounds.
Yesterday I was at the store, and I heard a baby start to fuss. I remembered this video, so I began to listen to see if I could identify what the baby was trying to communicate. Then suddenly I heard the "neh" as clear as day! I think this is amazing information, especially for parents of babies. (or in my case, future grandparents. :)