Generally used test samples can be found from:

http://www.ff123.net/samples.html
http://lame.sourceforge.net/gpsycho/quality.html
http://sound.media.mit.edu/mpeg4/audio/sqam/

Thanks !
Does anybody test them? +1000 files

I'm sorry but it seems I can't download the testsamples on the lame homepage anymore. Does anyone know where to get them?

-fLOh