While you don't have much space in a dorm, you can still arrange it to minimize intrusive sights and sounds. One simple fix is setting up a folding screen between each roommate's living area. Beaded or fabric curtains are another option. Sliding panels are more substantial, standing about 7 feet (2 meters) tall. They can also be more expensive. Use rugs and wall hangings to absorb sound.
You can also arrange existing furniture to maximize privacy. Move the beds to diagonally opposite corners. Then build walls by placing a chest of drawers, a desk or a bookshelf facing the bed a few feet away. Top with a microwave oven, a row of books or a potted plant to add height. One disadvantage to this type of arrangement is that you may lose precious space. It can also make for some inconvenient traffic patterns.
Many schools give you the option of lofting one bed, which simply resembles a bunk bed without the bottom bunk. This not only allows more privacy for the loftee, but frees up floor space -- to hang a curtain and make a changing room beneath the bed, perhaps.
Remember that you don't have to share space equally. If one person feels he or she can get by with a smaller space, it's an act of kindness to let the dorm mate appropriate the larger share. It's also a bargaining chip if a favor is needed.