Self-organisation in vowel systems Bart de Boer June 1999 Now Assistant professor at the AI department of Rijksuniversiteit Groningen 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 The AI-lab context PhD 1994–1999 Postdoc 1999–2000 en 2002–2003 Cooperators: Paul Vogt, Tony Belpaeme, Edwin de Jong, Jelle Zuidema, Joris van Looveren, Joachim de Beule, Bart Jansen, Bart de Vylder The transition from robotic work to evolution of language work 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 The context Explain universals of vowel systems Why are do certain (combinations of) vowels occur more often than others (acoustic distinctiveness) How does the optimisation take place? Unsolved problem in phonetics 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 The question Hypothesis Self-organisation in a population under constraints of production, perception, learning causes optimal systems to emerge Model Agent-based model Imitation games 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 The model For vowels: Realistic production articulatory synthesiser (Maeda, Valleé) Realistic perception Formant weighting (Mantakas, Schwarz, Boë) Learning model Prototype based associative memory Sounds Production Perception Associative Memory 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 The interactions Imitation with categorical perception Humans hear speech signals as the nearest phoneme in their language (?) Correctness of imitation depends not only on the signals used, but also on the agents’ repertoires Initiator Imitator 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 Imitation failure Initiator Imitator 50 jaar AI symposium, Brussel 2006

Interactions – the imitation game Imitation with categorical perception Humans hear speech signals not continuously, but as discrete categories Correctness of imitation depends not only on the signals used, but also on the agents’ repertoires Imitation game has later been used in robotic experiments as well 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 Results Imitative success Energy of vowel systems (Liljencrants & Lindblom) Size Preservation Success of imitation between agents from populations a number of generations apart Only in systems with changing populations Realism 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 Impact Result: The Journal of Phonetics paper is highly cited in evolution of language research and phonetics. Evolutionary approaches are now gaining currency in linguistics Method: Using agent-based computer simulations is nowadays an accepted way of investigating linguistic questions. This method has been pioneered in Brussels. 50 jaar AI symposium, Brussel 2006

50 jaar AI symposium, Brussel 2006 The future The application of AI-techniques to social sciences and humanities is wide open and full of opportunities Agent-based models in economics Agent-based models and GIS in social geography Linguistics The same relation between macro- and microbehavior (language level vs. individual level). Agent-based modelling contributes Application of speech recognition/synthesis techniques to linguistic questions 50 jaar AI symposium, Brussel 2006