Emotional information included in the voice is strongly influenced by its acoustic parameters. On the assumption that the emotion of sudden emergency is a mix of 'surprise' and 'fright', we have started a study to distinguish sudden emergency voices of the Japanese vowel [a] from ordinary voices using [a] by analysis and comparisons of acoustic parameters included in these voices. And our final purpose is to establish a method of an urgent stopping of the winch by the distinction of a sudden emergency voice, [a]. In this paper, we investigated the change of pitch frequency (F0) and the duration of the vowel [a] voiced imitating emotions by vocalists, and we explored the parameters which enables one to distinguish [a] voiced in a sudden emergency. As a result of this investigation, we see that the parameter of distinction is the START value on the F0 curve. If this value reaches l.71 times higher than the F0 of a neutral emotion, we can see that the voice has been uttered in a sudden emergency.
