If you want to emulate this purely in software there are convolution reverbs[1] available for both Pure Data[2] and Csound[3] that you could probably re-purpose / script to do tens or hundreds of iterations on any input material you wanted.

Note: the linked examples are both based on "partitioned convolution" algorithms[4], which allow lower latency than standard convolution algorithms, and would probably be a better choice for running many iterations in a reasonable amount of time.

I may play around with this when I next have some spare time.

[1]: https://en.wikipedia.org/wiki/Convolution_reverb

[2]: http://puredata.info/Members/bensaylor/partconv~-0.1.tar.gz/...

[3]: http://www.csounds.com/manual/html/pconvolve.html

[4]: http://cnmat.berkeley.edu/system/files/attachments/main.pdf