1. preventing sound from passing through

1. to make something resistant to the passage of sound

Examples

• The recording studio has soundproof walls.
• We need soundproof windows to block the traffic noise.
• The apartment’s soundproof doors keep out hallway sounds.
• They decided to soundproof the basement for band practice.
• The contractor will soundproof the home office next week.
• Double-pane glass helps soundproof the bedroom.
• We’re planning to soundproof the nursery before the baby arrives.