Speech is uniquely human among species’ communication abilities.

Evidence

Speech, as a means of linguistic communication (O’Shaughnessy, 1987), is a uniquely human process that is not found among other species of the world. It is so self-evident an ability that we often don’t notice how complex and delicate it is until something goes wrong with it. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 541