Things You'll Need
Egg crate foam
Soundproofing with egg crate foam is an easy project for any homeowner who needs a little more privacy. Just one layer can greatly cut down on how much sound moves through a wall. Whether you want to build an in-home recording studio or just think your bedroom wall is too thin, this project is within anybody's abilities.
This method assumes you want quick and easy soundproofing that you can remove later without damaging the walls. However, you can modify this framework for more permanent installation without much trouble.
Measure your wall using the measuring tape. You'll need height and width. You won't need to calculate square footage.
Find the dimensions of the egg crate rolls you intend to use. Figure out how many you'll need. For example, if your rolls are two feet by eight feet and your wall is ten feet by eight feet, you'll need five rolls.
Buy your egg crate rolls. You can find them at your local craft shop. Buy the thinnest, cheapest rolls you can find. The difference in sound reduction will be minimal. Do not buy your rolls at a camping supply store. Those are often waterproofed and always more expensive.
Cut off the excess with the utility knife and a straight edge if you need a partial roll to cover your wall.
Unroll the first foot of one egg crate roll. Use your staple gun to staple the edge even with the top edge of the wall. Put staples in dimples of the egg foam, using one staple for every two feet or so. If the roll is less than two feet wide, use one in each corner.
Unroll the rest of that egg crate roll. Staple it in place, still with the staples approximately two feet apart. Run another line of staples down the center, halfway between the lines of the other staples. The end result should look like a "5" on dice, dominoes or cards.
Repeat with the remaining rolls until the wall is completely covered.
Add a second layer running perpendicular to the line of the first layer for heavy-duty soundproofing. If the first layer of egg crate has seams running from floor to ceiling, your second line should lie with the seams running from one side of the wall to the other.
Even though this is an easy and reasonably safe project, be sure to take proper safety precautions with any home improvement task. Use a ladder if you need to reach the top of the wall and wear eye protection while using the staple gun.