Pipa is a new ‘expressive’ vocal synth plugin from Klevgrand that, although based on the human voice, isn’t designed to emulate all aspects of it.
This sounds like another way of saying that you shouldn’t expect maximum authenticity; what you are promised is “an organic and musical sound” and the option to tweak formants and dynamics.
Pipa marries wavetable and granulating synthesis - it contains thousands of wavetables extracted from real vocal samples. You can morph continuously between formants, dynamics and pitch - each parameter has its own envelope and LFO - and both male and female voices are included. Effects include room simulation and reverb.
You can find out more and download a demo on the Klevgrand website. Pipa is available for PC and Mac in VST/AU/AAX formats (64-bit) at an introductory price of $24.99, and as an iOS AUv3 for the introductory price of $9.99.