What is ActiveNoise?


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Noise cancellation, the stone-age way

Up till recently, the only manner of counter-acting noise, was to build noise walls or fit insulating, noise reducing materials around the noise-generating entity.

picture by: Acousticalsolutions.compicture by: http://ailsoundwalls.com

This was either horrifically expensive, or inpractical because you don't build a wall betwee two office desks in the event of noise.



How Active Noise cancellation works

Noise-Canceling headphones are gaining in popularity these days. Our devices take noise cancellation to a whole next level. This article will help clarify the technology used on noise-canceling products and provide a basic understanding of how noise-cancelling works.

Sound Frequency DiagramBefore we start, it is important to understand the difference between active noise cancellation and noise isolation. "Isolation" refers to using material and/or design to minimize external noise pollution. "Noise cancellation" refers to eliminating sound waves with other sound waves.

Noise cancelation technology is based on some very basic principals of sound. Take a look at the diagram on the right. Depicted is an example sound frequency. "Frequency" refers to the length of a sound wave (the distance from one peak to the next or one trough to the next).

Now, if we want to "cancel" this sound frequency, we will need to eliminate the peaks and troughs so that the line appears flat (silent). The simplest way to achieve this is to introduce the exact same sound (frequency) but out of phase. Phase is a word that describes the timing of a frequency. When two of the same frequencies occur simultaneously with synchronized peaks and troughs we call them "In Phase". When their peaks and troughs are opposing we call them "Out of Phase" The diagram below shows our initial frequency and our introduced frequency, both in and out of phase.

In and Out of Phase Diagram

When we introduce the same frequency out of phase of the initial frequency, the troughs of the out of phase frequency line up with the peaks of the initial frequency. When combined, the two frequencies create a flat line with no peaks or troughs. The sound frequency has been effectively canceled. (see diagram below)

Cancelled Sound Frequency

How the Noise-Canceling devices from ActiveNoise work:

Our Noise canceling products operate based on the sound principals described above. All our noise canceling devices utilize several components to eliminate external noise. The process begins with a directional microphone that senses incoming sounds of a particular direction. The microphone passes the signal to a processor which determines the frequency of the incoming noise, and creates and out-of-phase version of the incoming frequency. The new (noise canceling) frequency is then emitted from an array of directional speakers. This process requires power so most noise canceling products require electrical power.

How Noise Canceling Headphones Work

This article is intended to offer a quick summary of noise canceling technology. A quick internet search will yield more in-depth information.



Technology and application

Using unique Digital Signal Processing (DSP) technology, the ActiveNoise noise elimination products remove unwanted noises coming from a particular direction, processes these signals and sends a cancellation wave along to cancel out the noises, reducing the ambient noise level, reducing stress and enabling people to concentrate more on what is actually being said.

ActiveNoise uses the state of the art computer products that have appeared on the market in resent years and combine these with clever software and DSP processing the signal. The DSP technology is fully adaptive and no adjustments are necessary.

The signal is constantly monitored, and the DSP automatically adapts to any changes in the signal conditions.

Which sounds can ActiveNoise remove?

Noise can come from two areas

  • Transmitting end (picked up by a directional microphone from within a noisy environment)
  • Transmission process (interference) and Transmitting noise source.

This type of noise is picked up by the directional microphone, processed by our KILLER software and send back to the directional speakers. This way we can cancel out or significantly reduce noises of many kinds, for example:

  • Road noise
  • Engine noise
  • Wind noise
  • Crowded environments
  • Machinery and equipment
  • Transmission noise (Interference)
  • Weather
  • Other transmitted signals from >20hz

The answer is ActiveNoise!

Our devices create a sound wall, cancelling out noises coming from one direction to the place where you and your family are.

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Interested? See this product in our store or look at some videos about it.