In general the more the better. I'm not sure how long your audio files are but probably 32 GB is plenty. I have 32 GB and deal with images, which are usually way bigger than audio files and that's fine for me in most situations. Just booting and running Outlook, Firefox, MATLAB will usually take up about 14 GB or so, so 16 GB would not be enough, but 32 GB seems to be okay. I rarely, if ever, get close to 32 GB being used, even with lots of images open. If your audio files really long (gigabytes worth) then you might see if you can get more than 32 GB if you can afford it.