How do noise cancelling headphones work?

Advertisement
Advertisement
Deborah Davis
OBGYN (Obstetrics & Gynecology)
Noise-cancelling headphones reduce unwanted ambient sounds by means of active noise control.  This involves using one or more microphones placed near the ear, and electronic circuitry which uses the microphone signal to generate an "antinoise" signal.  When the antinoise signal is produced by the speaker driver in the headphone, destructive interference cancels out the ambient noise as heard within the enclosed volume of the headphone.
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
In noisy situations—doing yard work with power tools or maybe dinner with the extended family—it's worth using noise cancellation headphones, which emit energy in a frequency that we can't hear. The sound waves they create have the same amplitude but opposite polarity as the original sound; they combine with the external wave and effectively cancel it out so there's no sound at all.

Models available in stores typically cancel lower-frequency noises, while the ear cups themselves protect you from high-frequency noises. (By the way, there's no evidence to suggest that these devices cause any damage of their own.) If you are exposed to loud noises that come and go—sirens, trucks, traffic—cover your ears. And bring earplugs to weddings and bar mitzvahs.
You: Staying Young: The Owner's Manual for Extending Your Warranty

More About this Book

You: Staying Young: The Owner's Manual for Extending Your Warranty

International bestselling authors of YOU: The Owner's Manual and YOU: On a Diet give you all the tools and know-how to stay young and defy the ageing process. Drawing lively parallels between your...

Continue Learning about Ear, Nose and Throat

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.