M17 that I knew had 3big scars on his temporal side& on his right ear, apparently the cause of his deafness: what could've happened for him to have that? (image in description)

https://imgur.com/a/dk8kAAC

Here's a somewhat of a representation of it (not the best I am aware I did my best)

From what I know, this guy was a refugee& had to escape his country as a kid to get here. In his homecountry he apparently had an accident with debris that lead to that injury. He wasn't bald like in the drawing he just had short hair &you could easily see the scars whenever his hair got short enough.

I'm just curious of what possibly could've happened for him, we knew each other before but I never dared to ask him since I felt it would've been too much of a sensitive subject. I really don't get how such a scar could've lead to deafness.

Thanks in advance for anyone who's willing to help me figuring it out