After everything went black, i was hearing some loud echoing noise, like the wind was blowing into my ear. it's happen once before, but not recently.

Definitely see peds doctor: Again, if you're blacking out, and losing consciousness and hearing things, but not seeing anything, you need to discuss this with your pediatrician. It's very important that you have this looked into as soon as possible.

Blacking out?: I would be most concerned about why you blacked out. If you know why it happened (too much alcohol, etc), then you know how to prevent it from happening again. What happened after you blacked out isn't that relevant. But if you don't know why you blacked out, then you need to see your family doctor to help you figure out why it could have happened. You might need to see a few specialists.