soundproof

/ˈsaʊndpruːf/
adjective
  1. Designed to prevent sound from entering or leaving a space.
    • The recording studio has soundproof walls to keep out street noise.
    • They installed soundproof windows so the baby could sleep peacefully.
    • The apartment's soundproof ceiling stopped the neighbors' footsteps from being heard.
Antonyms
verb
  1. To make a room or building resistant to the passage of sound.
    • We need to soundproof the home theater so we don't disturb the rest of the house.
    • They spent thousands of dollars to soundproof their basement for band practice.
    • The contractor soundproofed the music room with special foam panels.