Thanks for posting,
That sounds to me like a nerve compression syndrome
. You probably slept on the left ear at night (you might say why that night?). Prolonged sleeping on that ear with a firm object could lead to that. The fact that the numbness
is getting even without any treatment simply indicates that decompression is occurring on its own. They are several nerve fibers that could have been compressed while you were sleeping.
I do not personally think that it is something you should be worried about.
hope this helps