Audio comparison engine

[dgsuarez]

It would be interesting to have a way to compare audio files.

As a first step, we can just convert the audio file into an image and then use the existing image comparator to do the comparison, here's a stackoverflow question with a way to do it:

• https://video.stackexchange.com/questions/22345/comparing-audio-waveform-in-a-visual-and-or-numeric-way