I don't know if you have experienced noise-canceling headphones in a noisy environment. The moment the noise-canceling switch is turned on, the quietness of falling into the deep sea is impressive. With the continuous development of ANC active noise reduction technology, earphones as small as the palm of your hand and cars as large as running around have been widely used, but do you know what ANC active noise reduction is?

Anc active noise reduction is a noise reduction technology, which is one of the methods of noise reduction in headphones. There are three noise reduction measures usually used to reduce noise, namely noise reduction at the sound source, noise reduction during transmission, and noise reduction at the sound source. Noise reduction at the human ear is passive.

In fact, the technical principle of ANC active noise reduction is not complicated. As we all know, the sound we perceive is transmitted through sound waves. The ANC active noise reduction technology collects ambient noise through a microphone, and then adds a reverse sound wave to the audio output through complex calculations, so that one positive and one negative cancel each other out, and we immediately feel the tranquility of the deep sea.

Sound is produced by the vibration of objects, and the propagation form of vibration in elastic media is sound waves. Sound waves in a certain frequency range act on the human ear to produce the feeling of sound. Noise is often defined as "unwanted sound" and is an environmental phenomenon. People are exposed to noisy environments all their lives, and noise is also an environmental pollutant produced by various human activities. Vibration is the reciprocating periodic motion of an object or part of an object along a straight line or curve and passing through an equilibrium position. It exists widely in nature and engineering.

Since vibration is the source of noise, in the practice of vibration reduction and noise reduction, the noise problem can be effectively solved by solving the vibration. In common noise control, thin metal plates vibrate, such as the tube wall of aerodynamic machinery, the shell of the machine, the car body and the hull, etc. are generally made of thin metal plates. When the equipment is running, these thin plates will vibrate and radiate noise. , the noise caused by the vibration of metal plate structure is called structure noise. For the effective control method of this metal plate radiated noise, one is to reduce the noise radiation area as much as possible in the design, and remove the unnecessary metal plate surface; Structural vibration and noise reduction, this method we call damping and vibration reduction is an active noise reduction technology.

Active noise reduction is to generate reverse sound waves equal to the external noise through the noise reduction system, neutralize the noise, and achieve the effect of noise reduction.