Seite 5: Phonology through imitation games

In another series of experiments, conducted together with Bart de Boer, we have shown that a phonology can evolve through imitation games.

The phonology consists of a repertoire of phonemes and phoneme segments which are admissable and distinctive in the language. Agents must develop both the capacity to produce the phonemes and the capacity to recognise them from acoustic signals.

An imitation game works as follows: A speaker picks a phoneme or phoneme sequence from his repertoire, or possibly creates a new phoneme or phoneme sequence by producing a random gestural score. A gestural score is a sequence of articulatory targets. The hearer then applies low level feature detectors to the signal in order to recognise the phonemes. When this recognition is successful, the hearer attempts to reproduce the phonemes again. The speaker now attempts recognition and can provide feedback on whether the result is compatible with the originally produced phoneme sequence.

Our experiments show that a common phoneme and phoneme sequence repertoire indeed develops and under the demands of the lexicon expands. The observed evolution in the complexity of the phoneme repertoire remains to be compared with what is known of natural phonological evolution.