The small round hole on the phone is actually a secondary microphone, which plays an important role in the dual microphone system that helps reduce noise. This is a noise-canceling microphone, which is integrated into most modern smartphones. Thanks to this microphone, your calls will be clearer and of better quality. Without it, your voice will not be transmitted clearly to the listener.

Even if there is a lot of noise around, you can still hear and transmit your voice clearly thanks to this small hole. Placing the microphone at the bottom of the phone close to your mouth helps your voice to be better captured and transmitted, improving the quality of the call.

The sound waves are transmitted through this microphone and amplified, helping the listener on the other end of the line receive clearer sound. Without a secondary microphone, the call quality will be significantly reduced.

Most mobile phones today have two noise-canceling microphones, one on the top and one on the bottom. When the phone is affected by environmental noise, the secondary microphone will reduce this noise, leaving only the sound of the call. This technology is called "dual microphone noise reduction technology", making the call clearer even in noisy environments.