Algorithm to achieve this result?

Hi.

I was trying to make a program that would take a bifurcation diagram,
like this:

http://www.chaos-101.com/wp-content/uploads/2008/01/bifurcation_diagram_540_400.png

(not a picture file, but calculated on-the-fly from the mathematical
formula (e.g. logistic map,
quadratic map, etc.) so you can tweak parameters, get the smoothest/
finest resolution, etc.
with minimum hassle.)

interpret it as a spectral graph like this:

http://www.icsi.berkeley.edu/Speech/mr/images/headset_spectrogram.gif

and turn that into listenable audio. What sort of algorithm would do
this? I could calculate
a slice of the spectral graph for a given sample and store that in an
array, but how do I turn
that into amplitude-representation (waveform)? My guess is it would
involve an inverse Fourier
transform, but how exactly would I use it to do this? Analyzing source-
codes for programs
that do similar stuff is not exactly an easy endeavor. Where could I
find a _good_ description
of this algorithm that is easy to follow?
.