According to the 9to5Mac, in the iPhone 12 series, Apple users can turn on or off their phone's noise reduction function through an auxiliary feature setting. This feature has never been open to iPhone 13 series users, and for an unknown reason, they have been waiting for several months, hoping that Apple can solve this problem. Recently, a Reddit user complained in a post that the iPhone 13 lacks a 'front microphone for noise reduction'. This setting can be used for auxiliary functions ->sound/visual. Although the user's description of iPhone 13 is correct, their claim that there are fewer microphones on iPhone 13 than on iPhone 12 is inaccurate. Other Reddit users correctly pointed out that this is not a hardware issue and pointed out the discussion on the Apple forum in October. Rpwils2 user wrote:

后来，一位苹果社区专家在一篇文章中指出，它可以帮助用户调整iPhone音频设置。(文字来源IT之家）

您可调节单声道音频和立体声左右声道平衡，以满足听觉需求。您也可以开启降噪来降低手机背景噪音。但问题在于iPhone13用户无法找到这种特定的特性。

手机噪音降低：当你把听筒放在耳朵上时，打开来减少环境背景噪音，iPhone调节音频。

另外一名用户dagocarlito在文章中表示，苹果公司已经意识到这一问题：

The option of 'never' on iOS15 for iPhone 13 is because it is a malfunction. I will discuss this matter with Apple's technical support personnel. This problem is already known and they are trying to solve it, but the timeline has not yet been determined. This also resulted in echo issues during calls between iPhone13 on CarPlay. This drawback is very serious and must be resolved as soon as possible.

The key is that this discussion needs to be traced back to October 29th, almost two months ago. IT Home has learned that Apple recently released iOS 15.2, but this issue has not been resolved, even in the iOS 15.3 beta version.

From the above image, it can be seen that the iPhone XS on the left has this feature, while the iPhone 13Pro on the right has no phone noise control. So far, the only feasible solution is to activate the voice isolation function in the call in the control center.