The mobile phone should not only receive the input sound, but also send the output sound. So there must be a receiver and a microphone. The receiver is located at the top of the phone, and the microphone is located at the bottom of the phone. The receiver is generally juxtaposed with the front camera in a strip shape, and metal grid lines can be seen. Whether it is a full screen or a non-full screen, try to make the sound direction of the receiver perpendicular to the screen, because it is the clearest when we put it in our ears to answer the phone.
There are also two holes at the top, one large and one small. The big hole is the antenna signal receiving hole, and the small hole at the bottom is the "noise reduction Mai Kong", which is mainly used for shielding and filtering external noise and interference. This technology is called dual microphone noise reduction technology, which reduces environmental noise through two microphones. It is said that its working principle is that the system filters out the parts with close decibels from the environmental sounds collected by these two microphones and judges them as noise. Release the opposite sound wave as compensation, effectively offset this part of the sound, and finally only output pure human voice.
With these two microphone holes, even if you make a phone call in a noisy environment, you don't have to worry about the call quality.
Then what are these five holes for?
It is both a speaker and a receiver.
As a speaker, it is used to play the audio information sent by the mobile phone. Such as music, video, ringtones, etc.
As a receiver, it is used for recording, that is, transmitting what you say to the receiver of the mobile phone. Keep your mouth close to the bottom of the phone when you make a phone call, so that the other party can hear your voice more clearly.
However, if there is too much dust blocking the small hole, the transmitted sound will be very noisy and the call quality cannot be guaranteed.
Don't poke these holes, or hundreds of dollars will be gone.
How do you usually clean these holes?
The easiest way is to clean with a soft brush (a toothbrush is also acceptable). Sweep all the holes of the mobile phone several times, then blow with a small hair dryer to clean up the dust around the holes.