I am playing a game right now and it is storming outside (yes, in game and not RL! lol) and I heard some lightening. I thought pretty cool =) Well, my idea is to lower the distance that you can hear it. The reason I came up with this idea is that during the storm, I went all the way down to bedrock to mine and could still hear the thunder! Now tell me, do you really think this is possible through all that earth, stone, gravel and stuff? I don't think so!
Maybe up to 20 or so blocks should be good.