If you have any queation, please contact us: (86-755)-84811973

Business New

1.Technical Analysis of Active Noise Canceling Headphones
1.1Analysis of the working principle of active noise reduction headphones Sound is composed of a certain frequency spectrum and energy. If a sound can be found, its frequency spectrum is exactly the same as the pollution noise to be eliminated, but the phase is opposite. Superposition in a specific space can be completely eliminated. Active noise cancelling headphones use this principle, the superimposed interference of sound waves in the space eliminates noise pollution. The system inside active noise canceling headphones collects and analyzes the noise, and then processes it through the built-in circuit to actively generate a noise of opposite phase, which can be canceled in a specific space. The low-frequency sound has longer sound waves, so it is easier to interfere with each other in the space, so the active noise-canceling headphone technology can effectively eliminate the low-frequency noise, and can also be used as passive noise-canceling headphones. Compensation for the frequency band.
2.2 Analysis of Active Noise Canceling Headphones Working System
At this stage, according to the working principle and design structure of active noise canceling headphones, they can be divided into two types: feedback type and feed forward type. Feed forward active noise reduction headphones are mainly composed of external microphones, secondary sound sources, internal components of the headphones, and active noise reduction circuits by moving the sound transmission position away from the secondary sound source. The sound port of the earphone collects external ambient noise. When the noise signal is collected by the external microphone, it will be transmitted to the secondary sound source through the ANC control circuit, and there is no feedback loop. Its corresponding parameters are often fixed, so it cannot perform rapid adaptive adjustment and phase control according to changes in the external environment, so its active noise reduction performance will be affected by external factors and become unstable, and it will play a role in some stable noises. It can produce good noise reduction effect, but the scope of application will be greatly limited, and it usually only appears in low-end headphone products. The main reason is that the headphone is smaller in size, and the internal design of the feed forward active noise reduction headphone can be more easily realized. Feedback active noise canceling headphones are mainly composed of internal microphones and secondary sound sources. It is composed of internal components of the earphone and active noise reduction circuit. The internal microphone is inside the earphone and is usually placed at the entrance of the ear canal. When the internal microphone collects the noise entering the earphone, it will be generated by the ANC noise reduction processing circuit. The phase is opposite to the amplitude. The secondary sound signal with the same frequency is finally transmitted to the secondary sound source, and the noise of the opposite phase is released through the secondary sound source, thereby realizing the active noise reduction operation. The internal microphone of feedback active noise canceling headphones is usually near the secondary sound source. By collecting the noise near the secondary sound source, a feedback loop will also be formed inside the noise reduction system, and then the parameters of noise reduction will be adaptively adjusted. The position of the internal microphone close to the secondary sound source can more realistically reflect the noise felt near the hearing, so the effect of noise reduction will be better, but the internal structure will be relatively complicated. In addition, due to the existence of a feedback loop, if the noise reduction system is not properly designed, unstable phenomena such as howling will easily occur, which is also a problem with this type of active noise reduction headphone technology. In recent years, the technology related to electronic products in my country has developed faster and faster, and the technology that combines feed forward and feedback has gradually become the focus of research. However, due to the size of the internal structure of the earplugs, some mid-to-low-end earphones on the market cannot effectively use feedback and composite noise reduction technologies, and most of them use a feed forward structure to achieve noise reduction.

In recent years, my country's electronic product-related technologies have developed faster and faster, combining feed forward and feedback
The combined technology has gradually become the focus of people's research. However, due to the size of the internal structure of the earplugs, some mid-to-low-end earphones on the market cannot effectively use feedback and composite noise reduction technologies, and most of them use a feed forward structure to achieve noise reduction.


Post time: Apr-20-2022