How to use VtubeStudio Voice Sync! Swap your mouth Open & mouth Form parameter inputs to VoiceVolumePlusMouthOpen and VoiceFrequencyPlusMouthSmile. If you have AIUEO params, be sure to add those in your custom params section. Alternatively, you can use the auto param setup under your Voice Sync settings! Then, add your mic in & calibrate each vowel by clicking the calibrate button and holding the vowel for a few seconds. These are based on Japanese あいうえお (AIUEO), NOT English AEIOU. Pronunciation