While headphones with active noise cancelling (ANC) technology have been around for a long time, the technology has progressed significantly in the past few years and has become much more common. Noise cancelling headphones can help keep you focused in a noisy office and block out engine noise on planes, trains, or buses. However, not all noise cancelling technology performs the same, and there are now many options in every price range, making it hard to know which ones are worth it.