Thank you for your support of the Xiaomi product. The noise in the earpiece of the POCO X7 during voice calls can occur due to a few factors. A common reason is the network signal quality, where some noise or distortion could be present in the voice signal during transmission, especially if the signal strength is weak or fluctuating. This can cause the voice to sound a bit blunt or unclear. However, this does not impact the normal functionality of the phone, and the call itself should still be usable.
Additionally, when dialing or answering regular voice calls, the phone uses algorithms to process the voice, which can soften the sound and reduce any potential noise. This is a designed feature that ensures the clarity of the voice call despite any network-related interruptions.