Impulse is a bit of eye candy for your desktop. It is a widget that displays a graphical spectrum analyzer on your GNOME desktop. It is written in C and Python, and uses GTK and Cairo graphics to generate the animation. The impulse library creates a pulse audio connection context that reads the output stream from pulseaudio in a thread natively, which can then be read from Python. You can instruct impulse to either output the raw stream or output the FFT of the raw stream.