Realtime art project --- input: sound --- output: image (better title?)
The above answer is a good one, PD is very flexible, but if you want something more code oriented and better suited to mixing with MCUs, processing might be better.
Another good way to do it would be to use Csound with the Csound Python API. Csound has a steep learning curve, but tons tons of audio analysis functionality and it's very good for running with low latency. You could definitely analyse an input signal in real time and then send control values out to a graphic environment, scripting both with Python.
I am not quite sure if I should ask this question here. 
I want to make an art project.
I want to use voice as an input, and an image as output.
The image changes accordingly to the sound.
How can I realise this? Because I need realtime or a delay under 50 ms.
At first I thougt it would be better to use a micro controller.
But I want to calculate huge images, maybe I microcontroller can't do this.
For example I want to calculate 10.000 moving objects.
Could I realise this with windows/linux/mircocontroller?
It would be very good if I could use Python.
Or do you thing processing is a better choice?
Do you need more details?