There is an urgent need for the comparative study, over as much of the world as possible, of the full range of paralinguistic phenomena — the kind of thing for which the linguistic field-worker is best fitted. Fact-finding, not theorising, is what is wanted at this present juncture.

Abercrombie, David. 1968. “Paralanguage.” International Journal of Language & Communication Disorders 3 (1): 55–59. doi:10.3109/13682826809011441.

That was almost half a century ago. Yet apart from some striking exceptions like Adam Kendon and David Wilkins, it is only since the last decade that fieldworkers have begun to collect multi-modal data in earnest.