impervious to sound.

verb (used with object)

to cause to be soundproof.

Origin of soundproof

First recorded in 1875–80; sound1 + -proof
Related formssound·proof·ing, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for soundproof

quiet, insulated, noiseless, soundless

Examples from the Web for soundproof

Contemporary Examples of soundproof

  • There would have been no birth certificates because Dugard was forced her to give birth in a soundproof structure in the backyard.

    The Daily Beast logo
    Why Jaycee Dugard Should Sue

    Wendy Murphy

    September 10, 2009

Historical Examples of soundproof

  • The wireless office was soundproof and practically airtight.

    Pincher Martin, O.D.

    H. Taprell Dorling

  • The booth was soundproof and all the lad did was to drop coins.

    Whispering Wires

    Henry Leverage

  • It was Lillian; she must have just come out of the soundproof speech-lab.


    H. Beam Piper

  • Yes, he could put up something big enough for everything the girls would need to install, and soundproof it.


    H. Beam Piper

  • But even if they had time to look it up, which they didn't, the contestant couldn't hear them in a soundproof booth.

British Dictionary definitions for soundproof



not penetrable by sound


(tr) to render soundproof
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012