On the Librem 5 when I am making calls, people tell me that on my end all they hear is my voice. But where I am calling from has a ton of background noise. Cars, wind, people walking around, and so they should be hearing some of that as well. But they all say that it sounds like I am alone in a room with nothing else.
I wasn’t aware that the L5 did something like this. Is this something that has been around for a while now?
Have you tried EasyEffects? It contains a noise reduction effect for input devices that you can try when using Pipewire. It’s pretty good to filter out background noise.
Note that the solution that PureOS uses only works with PulseAudio - it doesn’t work with PipeWire and as far as I’m aware distros that use PipeWire do not offer an equivalent solution yet. You can still use things like EasyEffects manually there, of course.
FWIW, aside of being a higher quality audio transport in general, VoLTE is irrelevant.