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Bluetooth headset noise reduction is divided into active noise reduction technology and passive noise reduction technology

Bluetooth headset noise reduction is divided into active noise reduction technology and passive noise reduction technology。

Passive noise reduction technology mainly isolates the external environment by surrounding the ear to form a closed space, or uses sound insulation materials such as silicone earplugs to block
outside noise. This sound insulation effect is completely realized by physical structure rather than electronic structure, and the cost is generally relatively low. In addition, due to the closed
Structure, wearing for a long time often causes ear discomfort。

Active noise reduction technology, also known as active noise reduction, is the use of microphone sampling Environmental noise, after data processing, it emits sound waves with the opposite phase to the noise to cancel the noise.
The concept of active noise cancellation was proposed by German physicist Lueg in 1936, and Bose launched the first active noise cancellation earphone product designed for aviation in 1989. At the beginning of its launch, it was mainly used in aviation, military and other fields due to its high cost. With the electronic technology With rapid development, noise-cancelling headphones have developed rapidly in the civilian field after more than ten years.

Active noise reduction technology uses the principle of superposition and cancellation of sound waves. sound waves
It is a kind of mechanical wave. When two signals with the same waveform and a phase difference of 180 degrees are superimposed on each other, an interference scene will be generated, and the two waves will cancel each other out. Based on this The realization of the active noise reduction system must first collect the surrounding environment through the microphone ,The noise signal of the environment, so when consumers use active noise-cancelling headphones,
You will find that there are one or two small holes in the fuselage, and the positions of these two small holes are the positions of the acquisition microphones, as shown in Figure 1 for the example of Huawei AM180 noise-cancelling headphones. Active noise-cancelling headphones currently have a lot of technologies and algorithms.
More precise noise reduction functions such as closed loop systems, open loop systems,
Adaptive Active Noise Cancelling Headphone System, etc.

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Post time: Apr-26-2022