Pulse noises during call too loud

Hi e.community, I wonder if anybody else faces this problem: during calls the other person hears quite strong “radio pulse” noises on my GS290. Different people mentioned that this is very annoying. With my speaker on I also hear these pulses. It’s stronger in situations with lower perception of the signal; but to some degree it is always there, even outdoors in a huge city while looking at a transmission station (radio mast). With my previous phone (Nokia Lumia 635) I never faced such issues.

Additionally, the quality of speech seems to be quite low - does this phone under eOS support HD codecs (AMR-WB, G.722.2)? The carrier network does, as I also know from my previous phone.

Anyhow, when will the GS290 enabled for VoLTE (including HD capability EVS)?

The GS290 now is running on the latest stable release of eOS for that model: v.18.

Anyone out there who also faces this problem?

Thanks in advance for your help,
T