Sony Xperia XZ Poor Call Quality and Strange Sounds

[Britannica]

I currently have the Sony Xperia XZ F8332 and have been experiencing poor call quality with quite audible strange sounds being heard in the background of a telephone call. The sounds are similar to a hissing sound and a screeching sound. They can be compared to the sounds that a wireless router sometimes makes while working. The other party tells me that my voice disappears during the call often and that it sounds like I am breaking up. I hear them breaking up too at times. This does not happen with every call. It is only some calls. I am concerned that this may be a hardware issue rather than typical interference and the such or possibly a software problem. Has anyone experienced this issue with the XZ and are there any settings I can change to possibly correct the problem? I am on the current software version. I do not have settings to change microphone noise supression such as was available on previous Xperia smartphones.

[MustangXperia]

I have the same problem but when calling some person. The equalizer to improve a calling quality does not exist for the xz! Why?

[Britannica]

Those settings have been removed from the software for the Xperia XZ and subsequent Xperia models. The poor call quality I keep experiencing is always in the same place so I can narrow the problem to being the signal reception in a certain place rather than the handset itself. However, my Z5 did well with signal reception in the place of question which leads me to believe that an antennae redesign or change in cellular radio that was implemented for the Xperia XZ has brought this signal reception issue about. 

[Abbyyy85]

I have been facing voice dropping issue for quite the past few weeks. Sometimes people tell me that my cell is coming as switched off even though it is switched on with signals.