@Erin is your little girl speaking now? Xx
Does he seem frustrated trying to communicate with you? I've been working with my one-year-old on telling us what she wants. She knows a few signs and it seems to help with the frustration. If he's having trouble communicating, I wonder if learning a few signs might help.
My daughter did this at 16 months too for about a month. It was so hard but I think she was just going through a stage x