Definition of noises off in US English:

noises off

plural noun

  • 1Sounds made offstage to be heard by the audience of a play.

    • ‘In Frayn's play, the noises off are the backstage screams and war cries of the actors who are all wrapped up in a farce of their own.’
    1. 1.1 Distracting or intrusive background noise.
      • ‘I found the noises off quite distracting.’
      • ‘Concentrate. Shut out all distractions, interruptions and noises off.’

Pronunciation

noises off

/nɔɪzɪz ɔf/