I guess I just never really thought about it…

From this piece on PsyBlog:

Lowering the lights signals the real beginning of night-time fun: with dimmed lights and alcohol beginning to work its magic the business of loosening up after the day’s exertions can truly begin.

But turning the music up so loud that people are forced to shout at each other doesn’t have quite the same beneficial effect on social interactions. Because everyone is shouting, the bar becomes even noisier and soon people start to give up trying to communicate and focus on their drinking, meaning more trips to the bar, and more regrets in the morning.

Read the full story for scientific details: When the volume is at 88db, you drink a beer 3 minutes faster than if it’s at 72db.