Spoken language is not a physical difference. Taken as a form of communication, it's not all that different from the rudimentary hoots used by chimpanzees to convey information to one another. Indeed, when it comes to learned languages, chimps, gorillas and orangutans pick up a rather complex understanding of human spoken language, and chimps and gorillas have proven adept at learning sign language or communicating through simple keyboards.
My dog understands English. Big deal.