Noise Reduction Headphones – How they work

The technology behind the noise reduction or cancelling headphones works by inserting a small (minuscule) microphone inside the headphones near the ear.  The microphone picks up on the incoming noise source (don’t think music yet) and then the circuitry generates an inverse sound wave that effectively cancels out the incoming noise.  The image below shows both the incoming noise source in red and the opposing inverse sound wave in blue.  The highs and lows of the red wave match the highs and lows of the blue wave.

How Noise Reduction Headphones Work

The technology behind noise reduction headphones has been around for quite some time, so it’s not something new, regardless of what many sales reps might try to tell you.  One of the leaders in this environment is Bose.  Bose actually made headphones for the NASA astronauts on the space shuttle.

Here’s a great video on YouTube that describes how noise reduction headphones work.

Do Noise Reduction Headphones Cause Cancer?

No – this is a myth that started with people thinking that putting a speaker near your ear is just like that of a cell phone.  It’s important to understand that cell phones emit a radiofrequency wave to communicate to/from a cell tower.  This radiofrequency is a form of non-ionizing radiation that is generated through the antenna when a call is made.  Noise reduction headphones do not emit a radiofrequency wave and therefore do not have the same potential health risks associated with a cell phone

Noise Reduction Headphones for Children with Autism

An interesting fact about Noise Reduction Headphones.  In 2015, the Hong Kong Journal of Occupational Therapy conducted a research study on the effects of noise reduction headphones on children with Autism Spectrum Disorder (ASD).  The effects of this study showed a clear linkage between the effects of noise reduction headphones and the ability to help children with Autism stay focused and on-task.  For more information on Autism diagnosis, check out the post by Fred Rexroat where he outlines the various types of Autistic characteristics.

Noise Reduction Headphones and the Affect Sound Quality

It’s important to understand how music and music compression works.  Music (today) can be broken down into 4 distinct types: High-Resolution Sound (the type of sound found at a sound-proof recording studio), CD quality music, Digital Music (MP3, MP4) and music you stream over the internet through companies like Spotify or Google Play.  Each of these media formats compress sounds into a bit-rate of kilo-bits per second (kbps).

  • High-Resolution Sound (sound recording studio) – 9,216kbps
  • CD Music – 1,411kbps
  • MP3 – 320kbps
  • Streaming Services (Spotify) – 160kbps

The higher the bit-rate (kbps), the richer and better quality the sound will be.  The lower bit-rates will produce a lower quality sound with losses of deeper bass and higher treble frequencies.  This explains why listening to a brand new CD at home sounds so rich compared to hearing the same songs over the radio.

Another great example would be listening to “Yeah” by Usher.  Listening in High-Resolution Sound, the bass booms and thumps and the “Yeah” chorus is rich and high with lots of highs, snaps and claps.  If you close your eyes, you can imagine Usher and his band in your living room.  Listening to it as an MP3, you’ve lost one-third of the sound quality.  The bass is only in the higher spectrum and the “yeah” sounds more like someone talking to you.

If you were an audiophile and lived to hear the strings of the violin in Bach’s Partita No. 2 in High Resolution or on CD, then to have that sound quality cut by 30% by compressing it digitally to an MP3 would be devastating and you would be very much aware in the loss of sound quality.

However, take the same audiophile and put them into an urban environment with a constant low-grade noise of automobiles and the hustle and bustle of people around, then perhaps noise reduction headphones would be perfect as they’re going to do a great job at blocking out that background noise.  As you’re already used to a bit of ambient noise in your apartment, the loss of sound quality will be miniscule.

Now where noise reduction headphones really work is when the technology is embedded in a headset and user plans on using it for gaming.  The sounds and music from your game system is usually run 320kbps or less, so the quality of the sound or music really isn’t that much of an issue.  By eliminating the background noise (computer power supplies, fans, other gamers in the same room), you’re able to really get into your game without any of the otherworldly distractions.

Additionally, not all noise reduction headphones are equal in their technology.  Some emit a low grade hum or hiss that you can pick up on.  Others have been known to produce quiet thumps.  As such, if you’re looking for noise reductionor noise cancellation headphones, it’s best to spend the money on a top-quality brand over a mid to low-end brand.

Pump Up the Volume

Surprisingly, that’s the exact opposite! As noise eduction headphones are removing or reducing the low-grade background noise, you’re actually able to listen to your music at a much lower volume.  This allows for a much richer sound experience, as you’re able to now hear the subtleties in the sound.  As we all know, listening to your music at a lower volume means less chance for hearing loss and damage.

Noise Reduction Headphones – Other Uses

TravellingSurprisingly, not everyone gets a pair of noise reduction headphones so they can block out the ambient sound of the environment around them.  A number of people swear by noise reduction headphones while travelling.  In the video I linked above, the narrator gave the example of how they’re able to reduce or remove the constant sound of the airplane engine.  For this reason, they’re great for travelling on trains and airplanes.

If you find yourself studying and cramming for exams at college or university, the constant background chatter and noise of fellow students can completely disrupt your train of thought.  Heck even if you’re someone who has an ADHD diagnosis and have a hard time focusing on tasks due to easy distractions, then noise reduction headphones can be a godsend.

Another use is for sleeping or listening to medication music or videos. The ability to cancel out the noise of your partner snoring or the drone of the city at night can lead to a very peaceful night’s sleep.

Noise Reduction Headphones – Conclusion

Hopefully you’ve found this post informative.  You shoud now be able to make an informed decision on if noise reduction headphones are for you.  One (actually two) last points – all the features of noise reduction headphones apply exactly to noise reduction headsets.  Lastly, the other factor that may sway your decision one way or another is price.  The technology behind the noise reduction can be costly and you can see significant hikes in the price of a pair of headphones over another that doesn’t have this feature.

Leave Your Thoughts Below…

One thought on “Noise Reduction Headphones – How they work

  • June 25, 2018 at 9:02 am
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    Great post on noise reduction headphones! It’s so interesting to know how music compression works. All in all very informative article and a great read. Thank you for the insight.

    Reply

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