Do you know anything about "Sudden Hearing Loss," like treatments and possible cures?

I received notification from a friend whom I have known for 48 years, mentioning that he woke up one morning (within the past 2 days), and couldn’t hear at all with his left ear, and tests measured a 50% loss of hearing in his right. Panic-stricken, he headed to his doctor, who diagnosed him with Sudden Hearing Loss and told him that an MRI was needed, to rule-out the possibility of a brain tumor.

I’m asking about the affliction here, because when I Google® it, I come up with a lot of contradictory information on it, and I’m not really sure if what I am reading is expert medical opinion, or some quack pretending to run a “medical-like” website.

One site purports that there is a 67% likelihood that the condition will correct itself, but I’m not all that optimistic, considering the kind of “luck” my friend has had, with 3 failed marriages.

If you have had this condition or know of someone who has, I’d be grateful for any information you can give me, regarding it.

Thanks, in advance.