You need an active noise canceling headphone if you want to block the ambient low-frequency noise, like engine noise in the airplane.
Active noise canceling (ANC) is different from noise blocking/isolating, which passively blocks both high and low-frequency noises.
This headphone guide explains what the active noise canceling (ANC) is and how the active noise canceling headphone works. It will not only help you understand ANC but also help you choose proper active noise-canceling headphones.
What is active noise canceling (ANC)?
Active noise canceling (ANC, aka active noise control) is a set of audio technologies which actively cancel the ambient noise.
Both the annoying noise and music reach your ear as sound waves transmitted through the air.
So, one simple way to reduce noise is to physically and passively block it. For example, there are many soundproofing materials and technologies.
In the airport, you may notice ground staffs are wearing earmuffs to block the engine and other noises In shooting club, it is also common that earmuffs are used.
Active noise canceling (ANC), on the contrary, uses negative sound waves to actively cancel the noise.
This means ANC requires at least three components:
- Power source. Active noise canceling (ANC) always requires a power source to detect and analysis noise and then generate a negative wave.
- Noise detection. Normally, one or more microphones are used to sample the ambient sound.
- Anti-noise sound wave generator. Once the ambient noise is sampled, active noise canceling (ANC) system must generate an inverted (negative) sound wave (with similar amplitude) to cancel the low-frequency noise.
When the ambient noise is canceled, you will get a quieter environment for your music.
Active noise canceling (ANC) is still evolving, especially on how to sample ambient sound, how to analyze the sampled ambient sound, and eventually how to effectively cancel the low-frequency ambient noise in real-time.
Please note, active noise canceling (ANC) currently is most effective for low-frequency noise only.
Active noise canceling (ANC) vs passive noise blocking
As discussed earlier, noise can be “blocked” (passive) and/or “canceled” (active).
Most headphones, in-ear or on-ear or over-ear, can block certain ambient sound. For example, some in-ear headphones are designed to seal the ambient sound. Of course, over-ear headphones usually can block more ambient sound.
For headphones, some manufacturers may also refer to noise-blocking as noise isolation.
Anyway, the differences between active noise canceling (ANC) … Read the rest