This paper reports on two experiments that tested the hypothesis that native phonology may influence speech perception. Both experiments used natural speech tokens of Standard Mandarin tones and Chinese- and American English-speaking listeners. The results from both the AX discrimination and the degree of difference rating experiments show language-specific effects: the Chinese-speaking listeners tone perception space was warped due to tone sandhi processes that neutralize two otherwise contrastive lexical tones. On the other hand, the English-speaking listeners showed phonetic listening, paying more attention to the similarity in pitch offset and onset between a pair of tones.