Talk about how mobile phones can reduce the noise of calls.

One is that the sound in front of the +A22 microphone is considered to need to be maintained and amplified normally, while the sound on both sides and behind it is considered unnecessary and needs to be reduced in volume. The technology is much better now. It actively identifies the nature of the sound, amplifies it if it detects the spectral characteristics of the language, and amplifies other sounds very little or gives waves with opposite phases, thus reducing the volume, thus improving the sound of the language and improving the clarity.