The self-organization of speech sounds

Abstract

The speech code is a vehicle of language: it defines a set of forms used by a community to carry information. Such a code is necessary to support the linguistic interactions that allow humans to communicate. How then may a speech code be formed prior to the existence of linguistic interactions? Moreover, the human speech code is discrete and compositional, shared by all the individuals of a community but different across communities, and phoneme inventories are characterized by statistical regularities. How can a speech code with these properties form?We try to approach these questions in the paper, using the "methodology of the artificial". We build a society of artificial agents, and detail a mechanism that shows the formation of a discrete speech code without pre-supposing the existence of linguistic capacities or of coordinated interactions. The mechanism is based on a low-level model of sensory-motor interactions. We show that the integration of certain very simple and non language-specific neural devices leads to the formation of a speech code that has properties similar to the human speech code. This result relies on the self-organizing properties of a generic coupling between perception and production within agents, and on the interactions between agents. The artificial system helps us to develop better intuitions on how speech might have appeared, by showing how self-organization might have helped natural selection to find speech.

Cultural evolution: implications for understanding the human language faculty and its evolution

“…Ultimately, all these design features will require such explanation, and a similar research effort aimed at understanding the evolution of duality of patterning (in both biological and cultural terms) is underway (see, e.g. Oudeyer 2005;Zuidema & de Boer in press). In §4, we will turn to the issue of interactions between biological and cultural evolutionary accounts.…”

The Recruitment Theory of Language Origins

“…On the other hand, it has been shown that those same universal trends reflect constraints of human embodiment (both of the articulatory system and the auditory system) as well as optimality constraints on sound recognition and sound reproduction [27]. Moreover recent simulations carried out in my group [12], [34] have shown that agents with similar embodiment constraints as human beings are able to autonomously self-organise vowel systems if they recruit a bi-directional associative memory to associate sound patterns with articulatory gestures. Even more interest-ingly, the emergent vowel systems have the same statistical distribution as observed in human languages (see figure 1 from [12]).…”

The evolution of case grammar

“…An example of a scaffold is the space of possible phonemes: in none of the experiments in this book, agents had to learn the distinctive sounds of their language. These "scaffolded" features may be brought in at a later stage or form the subject of other experiments, such as work on the emergence of vowel systems (de Boer 2000;Oudeyer 2005).…”

“…The above account of the history of the research on language as a complex adaptive system did not refer to the experiments on the emergence of vowel systems and phonology (de Boer 2000;Oudeyer 2005). I also left out the work performed on event recognition, but I will come back to this in Chapter 3.…”