Noise cancellation is a technology designed to reduce unwanted ambient sounds. It works by using microphones to pick up external noise and then generating sound waves that are the exact opposite, effectively canceling out the unwanted sounds. This is commonly found in devices like headphones and earbuds, allowing users to enjoy music or podcasts without distractions. There are two main types of noise cancellation: passive and active. Passive noise cancellation involves physical barriers, like cushioned ear cups, to block sound. In contrast, active noise cancellation uses electronic methods to counteract noise, making it particularly effective in environments like airplanes or busy streets.