Limitations of Noise-Cancelling Headphones

Noise-canceling headphones have several limitations that vary from brand to brand

- They need power, usually supplied by a battery that must now and then be replaced or recharged.
- They may not cancel all sound effectively. Some noise-canceling headphones can be overloaded by low-frequency pressure waves, distorting the desired signal.[citation needed] They work well for sounds that are continuous, such as the hum of a refrigerator or the sound in an airplane cabin, but are rather ineffective against speech or other rapidly changing audio signals.
- They may introduce additional noise, usually in the form of high-frequency hiss.
- Early models were much more bulky than traditional headphones.
- They are usually heavier because of the additional batteries.