Quick fixes for audio amplitude buffer to handle 16 bit stereo values instead of 32 bit mono.

The original implementation accurately represents amplitude, but since the audio buffer was read with 32 bit floats instead of 16 bit shorts listening to the waveform just gave you noise. Note that this only handles 44100khz 16 bit PCM audio used in the Clouds doc… a more robust implementation would look at the audio metadata and handle different sound formats gracefully.