In urban locations noise is a problem because you have neighbours surrounding you on all sides. Noise is a two way street. There's the sound that enters your home and the sound that's created in your home. Commercially available soundproofing products can be expensive and difficult to find. Many of these products are slightly modified versions of products you're familiar with such as caulking and insulation foam. By using a few commonly available home repair products you can save money soundproofing your space.
Walk through the room being soundproofed and find any openings where sound can enter or leave. Windows and doors are the first places that need to be examined. Tear off a piece of tape and place it next to each opening you find. Openings include loose window frames and door jambs. Mark off areas around wall pipes and anywhere else an opening exists. No opening is too small when sound is involved. Soundproofing specialists charge a great deal of money for on-site inspections such as this.
Measure your window frames for acrylic sheeting. The acrylic should cover the window frame not just the window itself. Use 1/8 inch thick acrylic for windows up to 24 inches by 24 inches and 3/16 inch thick acrylic for larger sizes. Measure the perimeter of any doors within the area to be soundproofed. Write down your measurements. Purchase sheet acrylic cut to your measurements, a roll of self adhesive foam stripping (1/2 inch thick), interior caulking, spray foam and Polyethylene close celled foam (if you need extra soundproofing for your walls). Standard Acrylic panels, caulking, foam strips and spray foam cost a fraction of their soundproofing counterparts and work just as well.
Caulk the windows at any point where you can feel air coming through. Apply the self-adhesive foam stripping to the inside of the door frames. If there is a large gap at the bottom of your doors, apply the stripping there as well. Use the spray foam to seal any open areas around piping. Inexpensive spray foam is just as dense as soundproofing foam and costs a lot less.
Drill holes into the acrylic panels no closer than 1/2 inch from the sheet's edges. The holes need to be slightly larger than the screw. Mount the panels to the window frames using screws. Use three screws along the top of the panel only. This allows the panel to be pulled open from the bottom in case of an emergency. The difference between commercially available Acrylic soundproofing panels and homemade panels is the mounting method and the higher cost of the commercial version.
Purchase and cut the polythene to size should you decide you need extra soundproofing. The foam should be placed on walls around the windows and doors. Use industrial double-sided tape to mount the foam. You can see how well the soundproofing works without the polythene foam before committing to it. Polythene foam costs a fraction of it's commercial counterpart.
You can approach this project in steps. Try caulking the windows and sealing the doors first. See if this provides sufficient soundproofing. If more is needed, seal areas around pipes and mount the acrylic sheeting. This combination usually reduces enough of the offending sound. Polythene foam should be used if loud music is involved. If you need a temporary sound barrier try hanging mover's blankets up on the walls, doors and windows. Old carpet, which can be found in thrift stores, can save you money on wall insulation as well.
Do not permanently seal doors and windows. In the case of a fire, these are your only exits. Remember, soundproofing a space also reduces airflow which can lead to health issues.