you might be interested in MetaSynth (http://www.uisoftware.com/MetaSynth/index.php) & Izotope's Iris (http://www.izotope.com/products/audio/iris/) which basically offer the converse of what you're doing here. fascinating from both a technical & a sound design point of view.

the former's what Aphex Twin used to insert his face into the Windowlicker"" spectrogram: http://en.wikipedia.org/wiki/Windowlicker#Background

edit: his face is actually in "[equation]"; "Windowlicker" has a spiral.