Neither Cantonese nor Mandarin has voiced stops. In Yale and Pinyin, t is aspirated as in English "tea", d is unaspirated as in the t in English "Steve". En

Neither Cantonese nor Mandarin has voiced stops. In Yale and Pinyin, t is aspirated as in English "tea", d is unaspirated as in the t in English "Steve". English does have the sound, but only as an allophone of t when it's preceded by s.