Vocal functional flexibility: what it is and why it matters

Human speech is marked by a signal–function decoupling, the capacity to produce sounds that can fulfil variety of functions, in contrast nonverbal vocalizations such as laughter, cries and screams, which are functionally more rigid. It has been argued this decoupling provides an essential foundation for emergence language, both ontogeny phylogeny. Although language deep evolutionary history, whether vocal functional flexibility also exists systems nonhuman animals much overlooked. Reasons multiple. Here, we propose diagnose problems have thus far hindered progress on understanding basis flexibility, issue shed broader light evolution language. In particular, aim clarify what is, why it matters, believe should be investigated how could best achieved.