[PD] Analysing sound for further processing > react with graphics

[Adrian]

Dear pdlist members,

i so far only used the graphical environment of pd. But now i'm
searching for ways how the graphics could react to sound. To things
like:

* tempo change
* volume change
* pan change
* spectrum change

can anybody send me some further info about how to analyse incoming sound?

-- 
another incomplete website: http://conficere.ch/pds