Back in the days I had a Processing sketch which visualized the computer's mic in some different ways:

• Big dots for frequency analysis.
• Some waveform of the input ( more in a artistic way)
• Some agent moving around, speed is controlled by the input volume

Plus rotation of the whole stuff which can be switched on or off, speed is also depending on the input volume.

Example (sorry no videgrapher here, just a guy with a smartphone ;) )