Seal gaps around doors, windows, vents, and outlets with acoustic caulk or weatherstripping
Add door sweeps and draft stoppers
Use thick curtains or blackout curtains over windows
Install removable window inserts or acoustic window film
Lay down thick rugs or carpets with dense rug pads
Hang acoustic panels, foam panels, or soundproof blankets on walls
Add bookshelves or filled furniture against shared walls
Use mass-loaded vinyl behind removable wall coverings
Place upholstered furniture to absorb sound
Use white noise machines or fans
Upgrade to solid-core doors if allowed
Cover hard surfaces with fabric, tapestries, or wall hangings
Use rubber or felt pads under furniture and appliances
Reduce vibration from speakers, TVs, and subwoofers with isolation pads
Rearrange the room so beds and desks are away from shared walls
Use door and window seals on balcony doors and sliding doors
Fill gaps around pipes and cable penetrations with acoustic sealant
Add ceiling treatments if noise comes from above and modifications are allowed
Use removable soundproofing panels for temporary solutions
Coordinate with neighbors or building management for recurring noise issues