We humans have some difficulty understanding bark and meow and other animal languages. Not everyone has the animal communication talents of Cesar Millan, the dog whisperer. Fortunately (for us), cats and dogs and other animals do not mind much for words. They do, however, mind very much about the tone of your voice and the body language that you use when addressing them. In simple terms, it means that animals can understand all human communication... if we do it right.