This paper shows how a society of agents can self-organise a shared vocalisation system which is discrete, combinatorial, and has a form of primitive phonotactics, starting from holistic inarticulate vocalisations. The originality of the system is that: 1) it does not include any explicit pressure for communication; 2) agents do not possess capabilities of coordinated interactions, in particular they do not play language games; 3) agents possess no specific linguistic capacities; 4) initially there exist no convention that agent can use. As a consequence, the system shows how a primitive speech code may bootstrap in the absence of a communication system between agents, i.e. before the appearance of language.
