My tablet won't give sound, even on notifications.

[AC Question]

Well, I haven't updated anything. Most of the time,the the problem is audio. I turn the sound completely up, still no audio. Once I downloaded Magic Piano. It buzzed when I play it. Even when my system was off, it still buzzed. I shut it down, and the buzz stopped. So I tried it with audio loss,and it didn't stop. Please help. Thanks.