4 ms·

This the same reason I stopped using my QC25’s i’ve often wondered if any other people may have had the same result. My logic was that they are creating opposi

This the same reason I stopped using my QC25’s i’ve often wondered if any other people may have had the same result. My logic was that they are creating opposing frequencies at the same level of sound pressure as the ambient you are trying to override meaning it’s still loud, just not in a perceptible way. So especially on airplanes, I now use earplugs instead.

sean1524 8y ago
Active noise cancelling does mean that the headphones create a sound wave which has the same frequency but is out of phase by a single wave length. This causes destructive interference which causes the total energy of the waves to equal zero. You are partially correct but active noise cancelling has the same effect as putting earplugs in due to wave mechanics. https://en.m.wikipedia.org/wiki/Wave_interference https://en.m.wikipedia.org/wiki/Wave_interference
- loco5niner 8y ago
  I believe that should read "has the same frequency but is out of phase by HALF A wave length". > active noise cancelling has the same effect as putting earplugs in due to wave mechanics. Simply from experience, I would disagree with this. Every time I have ever enabled active noise cancelling, I have experienced an increase in eardrum-pressure, volume, or both (both with and without music playing). I understand that wave mechanics would theoretically work as you state, but in practice, does not.
  - realityloop 8y ago
    I have to report the same experience, and I used to turn the volume right down when using noise cancelling too
  - coaxial 8y ago
    Same here, have tried QC25s and didn't keep them because it made me feel like I had a cold, gave me headaches, and felt like my ears were not equalized pressure wise. I use concert earplugs now, they are invisible unless someone really looks in my ears, and they attenuate all frequencies equally. This way I can also use them at concerts and they won't ruin the music, just make it much quieter across every frequency. The open office can't die soon enough, what an absurd fad this is.

sean1524 8y ago

Active noise cancelling does mean that the headphones create a sound wave which has the same frequency but is out of phase by a single wave length. This causes destructive interference which causes the total energy of the waves to equal zero. You are partially correct but active noise cancelling has the same effect as putting earplugs in due to wave mechanics. https://en.m.wikipedia.org/wiki/Wave_interference https://en.m.wikipedia.org/wiki/Wave_interference

loco5niner 8y ago
I believe that should read "has the same frequency but is out of phase by HALF A wave length". > active noise cancelling has the same effect as putting earplugs in due to wave mechanics. Simply from experience, I would disagree with this. Every time I have ever enabled active noise cancelling, I have experienced an increase in eardrum-pressure, volume, or both (both with and without music playing). I understand that wave mechanics would theoretically work as you state, but in practice, does not.
- realityloop 8y ago
  I have to report the same experience, and I used to turn the volume right down when using noise cancelling too
- coaxial 8y ago
  Same here, have tried QC25s and didn't keep them because it made me feel like I had a cold, gave me headaches, and felt like my ears were not equalized pressure wise. I use concert earplugs now, they are invisible unless someone really looks in my ears, and they attenuate all frequencies equally. This way I can also use them at concerts and they won't ruin the music, just make it much quieter across every frequency. The open office can't die soon enough, what an absurd fad this is.