Great idea! For anyone who wants to try it out without installing random software off the web, you can also view spectrograms with Audacity (and other stuff like Adobe Audition).

Anyone know any mac or linux equivalents? Would love to play with this.

Even better: First person to make a javascript version wins!

If I were to throw a js one together, I would use these as a starting point:

[0]: http://web-apprentice-demo.craic.com/tutorials?tutorial=33&d...

[1]: https://webaudiodemos.appspot.com/input/index.html

As per my other comment - Audacity can do this. The representation is called a spectrogram.

Edit: Oh and here's a JavaScript one. Haven't tried it as I don't have a microphone. https://github.com/sebleier/spectrogram.js/tree/master

'Spek'[0] is a nice free, lightweight, open source & cross platform Spectrum Analyser.

[0] http://spek.cc/

I don't think it's really an equivalent tool. As I understood, the main point is the real-time analysis of the microphone input. Spek seems to only analyze a « static » sound file (same for SoX and Audacity if I'm correct).

Oh thanks, I'd missed the "live" part.