The function of active noise reduction is to neutralize noise by generating reverse sound waves equal to external noise through the noise reduction system, so as to achieve the effect of noise reduction. Passive noise reduction headphones mainly form a closed space around the ear, or use sound insulation materials such as silicone earplugs to block external noise.
Noise-reducing headphones adopt active noise control, which is different from the passive sound insulation of general headphones. Its principle is:
1. First, use the signal microphone placed in the earphone to detect the low-frequency noise in the environment that the ear can hear (100 ~ 1000 Hz).
2. The noise signal is transmitted to the control circuit, and the control circuit performs real-time operation.
3. Play sound waves with opposite phases and the same amplitude through hi-fi speakers to eliminate noise.
4. After superposition, the noise disappears and can't be heard.
The first is business people. Because of frequent business trips, especially business people who travel between different cities every day, they must hate the noise in the cabin. If they have a noise-reducing earphone, they will be able to stay away from these noises and relax by listening to music.