@sandbags file don't need to be the same size, but me thinks it needed to be recorded in the same bitrate - 352kbps you can use the one from this post
in an ideal situation, override folder should be empty because all the game files are stored in *.bif files, but, since we're livin in "patched" and "modded" world all updated files are stored in override folder, these are files that override the ones that exists in *.bif's
let's say you don't like the custom Minsc portrait and thou wish is that Boo should be in the center or smth, so you put a files named NMINSCL.BMP NMINSCM.BMP NMINSCS.BMP in the override folder.
simply put, if in override exists the same file as packed in *.bif than the game will use the one from override.
I may have made a mistake but the general idea is as described above.
here, catch it: http://www.filesonic.com/file/2187361841/PAPER.WAV
it's not perfect since it's 4 sec of silence but I'm lacking any soft to edit it further.
Gwai, thank you that's great. A few less paper cuts while I play :)