The way to stop the common problem of a noisy home office (other than evicting all teenagers) is to block the avenues sound uses to get into the room. Sound transmission reduction is a complex subject, but keep it simple by considering this basic scenario: A massive wall, whether it’s concrete or built-up drywall, is a great sound absorber and blocker, but it becomes useless if there’s even a tiny hole in it.
Start small. First seal openings into your office, and then consider strategies for absorbing more of the sound as it passes through the wall, ceiling, floor and door materials.
Try these solutions in the order shown.
Install a solid-core door with vinyl weatherstripping and a bottom sweep and threshold.
Caulk around ductwork and electrical boxes where they penetrate the drywall.
Glue a layer of acoustic board and then another layer of drywall over the existing interior walls. This is a bigger project. It requires extending or moving electrical boxes, adding jamb extensions to doors, and removing and reinstalling casings and baseboard.
If the noise is coming from upstairs, nail furring strips on the ceiling with rigid insulation in between. Run the strips perpendicular to the joists. Screw resilient channel to the furring strips, then hang drywall from the resilient channel with drywall screws. Tape, sand and paint the ceiling. Electrical boxes and heating registers will need to be extended or moved downward. Another big job.
Glue a layer of acoustic board and drywall inside a stud space that’s being used as an air return. This will reduce the amount of return airflow by about one-third. Consult with a heating contractor to ensure that this won’t compromise your heating system.
Install rigid foam insulation board or fiberglass batts behind and around ductwork and electrical boxes. You have to tear open walls.
Fill wall and ceiling cavities with fiberglass insulation batts. If you open a wall for any another reason, add this step.
If the noise is coming from below, loose-lay acoustic board under the carpet. This requires pulling up the existing carpet and tack strip, installing new tack strip and restretching the carpet.
How to Soundproof a Home Office: Required Tools
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
Caulk gun
Circular saw
Dust mask
Hammer
Screw gun
T-square
Tape measure
Utility knife
If you’re tearing open the wall to add insulation behind electrical boxes, you’ll need tools to retape the walls, apply joint compound and repaint. If you’re installing acoustic board under carpet, you’ll need carpet stretching tools.
How to Soundproof a Home Office: Required Materials
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here’s a list.
Furring strips
Rigid insulation
Screws
Drywall
Acoustic board
Caulk
Construction glue
Door sweep
Foam insulation
Resilient channel
Solid-core door
Vinyl weatherstripping
Source: https://www.familyhandyman.com/project/how-to-soundproof-a-home-office/