Active noise reduction headphones are relative to passive noise reduction headphones. Active noise reduction headphones use DSP to eliminate external noise. Headphones have a built-in microphone and audio processing unit. When there is noise around, active noise reduction will neutralize and eliminate the noise through the completely opposite sound generated by the processor.
Active noise reduction headphones are mainly effective for low-frequency and medium-frequency noise, but not obvious for high-frequency, which is also to ensure that users can't hear external sounds when wearing headphones. High-frequency noise is generally a sharp sound, such as the whistle of a car. Users can at least hear high-frequency sound when wearing active noise-reducing headphones on the road to ensure the safety of users.
For example, the noise in the subway is just 80 decibels. If people want to answer the phone, watch videos and listen to music comfortably in the subway, they often need to turn the volume above 90 decibels to cover up the external noise, which may damage their hearing. Noise-reducing headphones have a good isolation ability from external noise, and the noise that may be heard after wearing them is only 40 decibels. At this time, you can have a good musical experience by adjusting the music to 60 decibels, which actually protects your hearing.