Distributional training of speech sounds can be done with continuous distributions

In previous research on distributional training of non-native speech sounds, distributions were always discontinuous: typically, each of only eight different stimuli was repeated multiple times. The current study examines distributional training with continuous distributions, in which all presented tokens are acoustically different. Adult Spanish learners of Dutch were trained on either a discontinuous or a continuous bimodal distribution of the Dutch vowel contrast /a/-/aː/. Both groups improved their perception of the contrast; this shows that continuous training works equally well as discontinuous training. Using the more natural continuous distributions is therefore recommended for future distributional learning experiments.