try this...
private void Command1_Click(object sender, EventArgs e)
{
SpVoice vox = new SpVoice();
vox.Speak(this.Text1.Text,SpeechVoiceSpeakFlags.SVSFlagsAsync);
vox.Viseme += new _ISpeechVoiceEvents_VisemeEventHandler(vox_Viseme);
}
void vox_Viseme(int StreamNumber, object StreamPosition, int Duration, SpeechVisemeType NextVisemeId, SpeechVisemeFeature Feature, SpeechVisemeType CurrentVisemeId)
{
this.Text2.Text = this.Text2.Text + CurrentVisemeId + " ";
}