If a person is trying to hear an important part of a lecture, they don't want someone to drive by with their music and bass blasting. They could miss out on something vital if that happened. There have been studies done on the affects of noise and the work efforts. They could go home with headaches and drowsiness, making them not want to show up everyday. It makes sense, if a person knew that by the end of the day they would feel bad, they would be less likely to go to work.
Sleeplessness is a problem that everyone has experienced.
This is usually because some noise is keeping them up. If there is a constant irritating little drip coming from the sink in the next room, a person would more than likely not be able to put it out of their head, causing them not to sleep well. As a person grows older however, their senses start to pick up more noise, causing them to wake up. A person needs sleep to get through the day, and not just any sleep. To function effectively through the day, one must have good, sound sleep.