was ok a few weeks ago, but now the dialing tone sounds strange and when I ring out or receive a call the person at the other end canot hear me but I hear them and they sound robotic and crackly
I presume you've you've removed and replaced the phone plug into the wall socket to make sure it's clean.
Could be a bad connection in the street cabinet in which case an engineer callout will be needed.
Also check you haven't got a crossed line ... dial 174 and an automated voice will tell you if you are still on the number you expect to be.
A few other people have the same problem,BS37 area.
Thanks for your post and welcome to our community 🙂
Have you tested another phone handset?
Let me know if this is something you still need help with.