I always suspected I had a small left Heschl's Gyrus

If the latest issue of Cerebral Cortex hasn't popped through your letterbox yet, you will probably have missed Patrick Wong's (and others) paper entitled: 'Volume of Left Heschl's Gyrus and Linguistic Pitch Learning'.

Basically, Patrick and his team tested the ability of adult native English speakers to learn tonal languages e.g. Chinese. He found a correlation between the size of the left brain Heschl's Gyrus and aptitude to learn these types of languages - the smaller the HG, the harder it was for the students to pick up the language skills.

Here I am wondering why I am making little to no progress with my Chinese classes when, in fact I am, most likely, genetically pre-disposed not to speak Chinese. It's probably an amazing feat that I speak as much as I do given the size of my left HG.