Dept. of Linguist., Univ. of California at Berkeley, Berkeley, CA 94720
Much research has been done on the cues differentiating the three Korean stops in word initial position. This paper focused on a more neglected area: the acoustic cues differentiating the medial tense and lax unaspirated stops. Four adult Korean native speakers, two males and two females, pronounced 16 minimal pairs containing these stops. The average duration of vowels before lax stops is 93 ms longer than before their tense counterparts (143 ms for lax versus 50 ms for tense). In addition, the average duration of the stop closure of tense stops is 178 ms longer than that of lax stops (74 ms for lax versus 252 ms for tense). These durational differences are so large that they may be phonologically determined, not phonetically. Moreover, vowel duration may vary with the speaker's sex. Female speakers have much shorter vowel duration before the lax stops. The quality of voicing, tense or lax, is also a cue to these two stop types, as it is in initial position, but the relative duration of the stops and of the preceding vowel appear to be much more important cues. The consequences of these results for the phonological description of Korean as well as the synthesis and automatic recognition of Korean will be discussed.