Soundproof means blocking sound from passing through walls, floors, or other barriers. A soundproof room keeps noise from getting in or out. Recording studios are soundproof so musicians can record without hearing traffic outside, and so neighbors don't hear drums at midnight. Libraries sometimes have soundproof study rooms where students can work without disturbing others.

Making something soundproof usually involves thick, dense materials that absorb or reflect sound waves. Some people add special foam panels to garage walls when they want to practice guitar without bothering the family. Apartment buildings try to soundproof walls between units so residents have privacy.

Nothing is perfectly soundproof, though. Even well-designed studios can't block extremely loud noises like jackhammers or thunder. The word can be used as a verb too: you might soundproof your bedroom door by adding weather stripping around the edges.

When something is soundproof, conversations stay private, practice stays productive, and everyone gets the quiet they need to focus, sleep, or work without interference from the noisy world outside.