Can you hear noise or crackling on your analogue telephone, here are a few things you can try to resolve the issue.
If you're using a cordless telephone, check that the batteries are charged.
Also check your telephone's connection to it's base station. Ensure the base station is connected correctly to the telephone line.
After hearing the your telephone number read out, press option 2 to run the test. You'll hear "Quiet line test" spoken on repeat. Listen out for noise between the prompts and hang up when you feel you understand if noise is or isn't there.
You can find a video on how to do this here.
If the above steps do not resolve the problem, please contact our Technical Support team for further assistance.