My Dad Has A Bump On The Left Side Of

My dad has a bump on the left side of his head near the ear. He says it's been ongoing for the past few months. There is tenderness in that area and he gets a lot of headaches. He is now starting to have ringing in the ear on that side.

Can somebody help me figure out what this can be. The doctors he has seen just tell him to take anti-inflammatories, but they do not help.