My son has a limited amount of words, was hard to understand when he did speak, and was sensitive to loud sounds. After starting therapy I can understand him better, he rarely covers his ears for loud sounds, and has a larger vocabulary. The most important advice I can give is to follow your instincts. Our pediatrician did not think my son had a delay, therefore we did not pursue therapy in a timely fashion. I wish I would have followed my gut sooner.