닫기버튼

Active Noise Control

Active Noise Control

Active Noise Control?

A technique to analyze the waveform of the sound at the place where the noise is
introduced and analyze it in real time(DSP - Digital Signal Processor) to generate
noise(Destructive interference) to reduce noise

Modern society is surrounded by car noises on the roadside, construction site noises, and many other noises that are heard in the surroundings. A passive method to block noise is the most typical way to avoid such noise. However, there is an active noise control technique, known as 'Active Noise Control.

Generally, noise reduction methods such as sound absorbing materials and sound insulation materials are the most inexpensive and effective methods. However, this has limitations in reducing noise. Also, there are inconveniences caused by the facilities. However, by using active noise control technology called ANC, it is possible to control noise with simple equipment. The principle of controlling the active noise is to cancel out the noise is to use the characteristic of sound, or wave to cancel the noise using superposition wave.

A device for analyzing the waveform of the sound is installed in the place where the noise is introduced, and it is analyzed in real time to generate the control sound to cancel the sound by canceling the sound wave. These technologies can be used in devices and facilities where the use of mobile phones and automobiles is remarkably effective when noise is removed.

Destructive interference : Interaction of two sound waves when two or more sound waves exist at the same time
  • Characteristics of Wavelength

    Active Reduction Effective in low frequency range
    Passive Reduction Effective in high frequency range
    Broadband Noise Passive and Active Noise Control is required
  • ANC Building Block

    Reference Mic Receive noise
    Controller Detect and monitor noise reduction
    Speaker Generate anti noise
    Error Mic Analyzes the noise sent from the Ref Mic to generate anti-noise of the opposite waveform on the speaker side