Scroust is a game about shouting. But being quiet. The competing players (or teams) draw either a 'high' or 'low' tone as their target. They must produce their tone audibly to score points, but if their tone is too loud, they will lose points much more quickly!
I was a programmer for Scroust, implementing the voice input. To be able to prototype quicker, I let Unity's audio system do the hard work, hooking up the mic input to an audio source which I passed through the built in high- or low- pass filter appropriatley. Unity won't process muted audio sources, which meant that mic input was included in the game's audio output. To solve this I implemented a dummy audio filter to be placed after the hp/lp filters which extracted the current audio data and returned a zeroed-out array back to the audio processing system.
Download it and shout quietly - For PC or Mac. (* Scroust was made in one week so doesn't have a mic calibration utility. Results may vary)