unaspirated sound
当辅音[p,t,k]出现在非重读元音前或[s]之后时,是不送气音(unaspirated sound),如pupil[′pju:pl],prety[′priti], taking [′teiki ]或sport [sp t], stand[stend], sky[skai]等。
Aspirated and unaspirated consonants ; the aspirated and unaspirated
voiceless unaspirated consonant
unaspirated stop