Problem with sound Google Pixel was fixed next update
We will remind, at the end of 2016 appeared the information that Google Pixel have problems with the loudspeaker, which Google can not be eliminated.
In January it was suggested that the problem is hardware, therefore no firmware update does not correct the situation.
However, as stated in a comment on Reddit, the February security update has eliminated the problem. Different users confirmed that they no longer hear the wheezing of a loudspeaker in a variety of applications. Although the description of the update focuses only on improving the signal quality when used with multimedia system Honda cars.
Perhaps, as in the case of an unofficial firmware, the developers only reduced the maximum volume of the speaker.