WONDER #1480: How Do Noise-Canceling Headphones Work?

Question 1 of 3

What does ANC stand for?

  1. active noise control
  2. passive noise control
  3. ambient noise control
  4. a noisy controller

Question 2 of 3

Who pioneered active noise control technology?

  1. Bose
  2. Sony
  3. Freud
  4. Kenwood

Question 3 of 3

Sound waves with frequencies exactly how many degrees out of phase with each other will cancel each other out?

  1. 90
  2. 180
  3. 270
  4. 360

Check your answers online at https://wonderopolis.org/index.php/wonder/How-Do-Noise-Canceling-Headphones-Work.