Problems with the newly released Google Pixel 2 seem to be growing every day. After a report on click and screen burns, a fresh complaint indicates that the audio quality in the video recording is below par. Low quality audio in video recording is likely to affect more background noise. From the video below, you can observe that the sound of water flowing at first is very clear and after a while, the quality turns bad before returning to normal at the end of the clip.
To be sincere, this is not a big deal and maybe this can be fixed through software updates. The problem has not caused a fuss, but a thread has been opened for him in the Google Support Forum and Google has confirmed the issue and promised to fix it.
The real cause of this problem is not yet known but there is a possibility that the algorithm for the echo cancellation / noise is too aggressive. Keep in mind that this issue is not addressed in all audio and it's possible that only devices will experience this.
Source : https://www.gizchina.com