Perceptual categories built up in the identification of speech sounds remain highly plastic in adults and continuously evolve along a wide range of time scales. Tuller and colleagues [1,2] accounted for this plasticity using a non-linear dynamical model in which perceptual categories are associated with attractors of a potential function. In this model, the availability of a percept, its stability and strength, are functions of the acoustic properties of the stimulus, the previous percept, and the combined effects of learning, linguistic experience and attentional factors. Importantly, this means that for some range of the acoustics, more than one category is possible. The switch from one category to another is governed by the loss of stability of the current percept. The rate at which this happens depends on a variety of factors including experience with the stimuli. On a local level, the less experience a listener has with the stimuli, the more acoustic change is needed to switch between categories. Here we explore the influence of long-term experience (phonetic training) on the listener's behavior. In addition, we extend Tuller et al.'s experimental paradigm to French within a different vowel context.