Author: 
He has learned to respond to many words in the past month — He’ll make the correct sounds for book, ball, Mamma, Dadda, and Grampa! [Alex’s inserted comment: for Grandpa, he’ll say in a sharp, short, urgent, agitated voice, “Hey!” No, there is no sound for book, Grandpa, or ball. But he tries to say the words]. He likes to make lion, elephant, cat, and monkey noises when you talk to him about those animals. His lion noise is a french gutteral RRRR, modeled after Alex’s Tigger impression. His stuffed lioness toy inspired this.
[Alex: He also makes these sounds when he sees depictions of these animals or stuffed animals. This morning I took him out and he saw a neighbor walking a dog. He flapped his arms and went “Da!” and started making something between a little and barking sound over and over again. – “Hmm! Hmm! Hmm! Hmm!”]