When I listen to music on my MacBook Pro (2012 edition) with my EarPods, I have the volume turned all the way up to 100%. While it's a little louder than it should be, it's nowhere near loud enough to be painful or affect me negatively. That being said, I was listening to music and then unplugged my EarPods, went to go talk to someone in my house, and when I came back, plugged them back in, and pressed play, I screamed. The volume was so incredibly loud that it stung. After then listening to various songs with the volume bar at 50%, I realized that the 50% level of the new volume power is equal to the 100% of the one I had a few minutes ago. I wasn't updating iTunes or tampering with my macbook's settings or anything, so what could've possibly done this out of nowhere? Thanks.