How do noise cancelling headphones/earphones work?

No ise - can cell ing head ph ones and ear ph ones work by using advanced technology to block out external noise . They typically use a combination of active noise can cellation and pass ive noise reduction to create this . \n \n Active noise can cellation ( AN C ) involves using a micro phone to detect and measure the sound waves that are entering the ear ph ones . This information is then used to generate an invert ed signal , which is played back through the ear ph ones to cancel out the external noise . This process is often referred to as " phase can cellation ." \n \n Pass ive noise reduction , on the other hand , re lies on physical bar riers to block out external noise . This can be achieved through the use of ear p ads or ear pl ugs that fit sn ug ly in the ear , creating an a irt ight se al that helps to block out sound waves . \n \n Some noise - can cell ing head ph ones and ear ph ones also incorpor a feature called " trans par ency mode ," which allows external noise to be heard while still providing noise can cellation . This can be useful in situations where it ' s important to be aware of your surr ound ings , such as when walking down the street or in a public place . \n \n Over all , noise - can cell ing head ph ones and ear ph ones are a great option for anyone who wants to block out external noise and enjoy clear , high - quality sound . </s>