What did you use to bump up the audio on it?
Audacity ... it's free and trivially easy to use
Just import your audio file and under Effects choose Amplify.
You can change how much you want things amplified BUT the default when you select it will automagically amplify bump things up to the max without "clipping".
FYI: clipping is where the signal hits the amplifier max and plateaus and anything above that point is lost aka cut off or clipped.