When you execute C2 and make a new project, there is actually a template named "Microphone input" that already modifies the Audio Analyser to use the microphone as input instead of a sound.
From there, according to the volume (the value of the RMS shown in the example: Audio.AnalyserRMSLevel("mic", 0) *2 or *4) you should be able to modify the Y position of your sprite.
The actions that modify the sizes of the sprites in the event 9 is very close to what you are looking to get.