As with windows, doors are a major culprit for letting sound leak in and out — even when they are closed. To develop a more efficient sound barrier around doors, swap hollow core doors with MDF or solid wood doors, and add closed cell foam tape or weather stripping around door frames. If you are on a limited budget, adding vinyl peel-and-stick soundproofing material to a hollow core door will increase its sound dampening ability to a degree as well. This is made especially for doors and comes in door-sized sheets. Whatever your choice, make sure you have a snug-fitting bottom door seal in place, too. If you have sliding glass patio doors, upgrade to acoustical soundproof glass doors or install sound dampening drapes.