For the money, Audio Osmosis is a lot of help. I listened to it some before my test, and did not do any formal studying (I did okay - over 24). I have them on MP3s in the USA, but just looked notw, and I do not think I have the file copy w/ me in MX.
Also, learn how to interpret their retarded reading sections ACCORDING TO THEIR INTERPETATIONS because it is ** and is nothing about English or comprehesion.
Of course, the USMLE is not about what you know, or how well you will do in med school, but a test of how well you can prepare for a test.
Also, go to HearMore.com where you can buy a watch (for the deaf) that has a vibroalert countdown timer. Also, use a 0.9mm mechanical pencil (not a 0.5mm) so you do not waste any time blackening the scantron if you take the paper test.
"You do not truly understand something unless you can explain it to your grandmother." Albert Einstein