Now, as an adult, I don't really care what people think of me and I can't stop singing. During the singing time at church, I usually am the one singing too loud. From time to time, there will be people that will turn around and look at me, smile and turn back around again. I know it's because I am singing so loud. They are probably thinking "Bless his heart... He's trying so hard..."
When I listen to myself sing, I do realize that I don't have that great of a voice - but it doesn't stop me.
In 2 Chronicles 30 we read "the Levites and the priests praised the LORD day by day, singing with all their might to the LORD." Perhaps what we can learn from this is that when we are in worship, we should be singing at the top of our lungs, with all of our strength, to the Lord.