Dealing with micro and sound FX

I had the idea of an funy app :

imagine an online phone with the possibility of having realtime FX on the voice. From dracula preset (dark reverb) to betty boop(pitch up), it could be a funy call !
And on Multiplayer games too !

Is it possible ?

For this you probalby should use an external DLL, written in C# or VC++ etc. However, you may try to achieve some FX with BlitzBass.dll and there's also an example on how to record sound in the code archives. Doing realtime voice communication over TCP is a further chapter and its complexity should not be underestimated IMHO.

You can't play Blitz audio in realtime while writing to an audio buffer. You ahve to create the audio and then play it. Blitz on it's own isn't going to manage any realtime audio effects.