FREEWARE: Vocov Vocoder

Vocoding is that robot vocal effect you get in tracks both old and new. This vocoder is a digital/analogue hybrid model for Windows that is free to download.

You can vocode and mix with two different engines: an FFT-based digital engine or a filter bank analogue version.
It works as a VST instrument with a special plug-in to handle the carrier and modulator components that are required for taking the input signal and using it to create the vocoded effect.

There’s a built-in eight-voice polysynth, plus the ability to use recorded audio as the carrier, up to four inputs to use as the modulator and a buffer freezing function. Six-band graphic EQ and an effects section with delay, chorus and reverb round out
the package.

Download here