The ability of native English (NE) and native Chinese (NC) speakers to identify and discriminate the mid-versus the lowtone contrast in Thai was investigated before and after auditory training. The variables under investigation were first language background and the interstimulus interval (ISI) of the presentation (500 ms vs. 1500 ms). The NC group outperformed the NE group in its ability to discriminate the two Thai tones under the ISI 500 ms condition before training and under both ISI conditions after training. A significant improvement in identification from the pretest to the posttest was observed in the NC group under both ISI conditions, but not in the NE group. These results suggest that prior experience with the tone system in one tone language may be transferable to the perception of tone in another language.