Tone languages, such as Thai, use pitch differences to distinguish lexical meaning. In this study, we investigated the effects of native language and training on speaker normalization in perception of lexical tones in Thai. Three tokens each of the Thai high, mid, and low tones were generated to simulate three female speakers with three relatively different F0 pitch ranges (high, mid, and low). The stimuli were presented to native Mandarin Chinese (NC), American English (NE), and Thai (NT) for categorization before and after a two‐day perceptual training. Results obtained thus far from 32 NC, 30 NE, and 11 NT suggested that, overall: (a) NC outperformed NE both before and after training, (b) NT numerically outperformed NC before training, but not after training, and (c) performance of all three groups of participants improved after training. Interestingly, it was also found that participants’ performance varied from tone to tone, depending on the tonal environment in which it was presented for discrimination. These results suggest that knowledge of a tonal language and perceptual training facilitates the speaker normalization process in lexical tone perception, and that tonal contexts affect discrimination of tones.