I have about a quarter sized hard lump above my left ear. sometimes i have ringing in my ear and i get bad headaches once in a while. tumor?

Please be examined: It is always concerning when anyone presents with a "hard" lump. A good history and physical by a physician along with any indicated tests will aid in diagnosing potential serious conditions.

Possibly: In medical terms, a tumor just means a "growth", it is not the same as "cancer" - so you can have benign tumors/growths and malignant tumors/growths. A quarter-sized lump is pretty big, so I would have it looked at by a Dr. as soon as possible to determine if it is benign or not. You don't need to rush to the ER, but make an appointment with a Dr as soon as you can.