First you need to open a terminal window and navigate to the folder where the bin and toc files are located. Next, you need to install some software to convert the bin files to wav format. You can apt-get it with the following command.
sudo apt-get install bchunk
Now, Brasero creates a toc file and you will need a cue file to run bchunk. So, you will need covert the toc file with the following command. The toc2cue should be install if not apt-get it.
toc2cue brasero.toc brasero.cue
The final step is to convert the bin file to the actual wav files. Make sure you use the flags -vws. If the wav file doesn't sounds correct try removing the -s.
bchunk -vws brasero.toc.bin brasero.cue brasero
The wav files should now be extracted in the folder where the bin files was located.