Forma-8

Forma-8 is a practical and powerful VST plugin that you can use to create audio transitions between vowels using an XY pad.
Basically, it’s a formant filter that allows you to move on the four corners of the XY axis system and morph between the vowels. A formant is an extension of the 'Wah' principle, a resonance in the human vocal tract that gives the sound a certain characteristic.
Forma-8 displays a more than comprehensive interface which makes it a cinch to use by just about anyone that understands how an XY pad functions. In all the four corners you get drop-down menus from where you can choose the type of vowel and voice that is processed. You can select between ‘ee’, ‘ae’, ‘ah’, ‘aw’, ‘u^’, ‘oo’ and ‘er’ vowels and mix them with female and male vocals that are either sung or spoken.
The plugin allows you to choose different arrangements for any of the four corners, giving you total freedom to create unique mixtures of sounds. This way, while a track is being played and Forma-8 is active, you can quickly pan the cursor on the pad and instantly or slowly transform the sound.
Besides the vowel and voice selections, you also get to adjust resonance and modulation for the effect. These, along with the use of the ‘Mix’ and ‘Volume’ parameters can give you an either subtle of powerful output.
In closing, Forma-8 is by all means an audio plugin that can definitely give you the right amount of audio transformation you need in order to add a human like voice effect to your songs.