How do I visualize a sound?

Works best with Firefox (version 47 or better), and also works in Chrome: click here to try this.
Click here: If you're getting Firefox permissions problems

Also available as a standalone Mac app: SoundViewer2.app.zip

Click "Go" then start talking. Hit the space bar to move from a signal view, to a FFT view, to a sonogram view.

Sonogram view:

sonogram-view.png

FFT view:

FFT-view.png

Signal view:

signal-view.png