I can hear my own voice on telephone calls
The symptoms are that an incoming call is received and as well as being able to hear the caller you hear your own voice delayed by 1 or 2 seconds, which makes having a conversation difficult.
To hear your own voice there has to be a loop somewhere on the network or at the far end sending your voice back to you. We know for sure that this is happening with some calls from Skype. We don't know if it is also happening with other services. This is a Skype (or other services) problem, or a problem with the configuration of the equipment being used by the person calling you. This is not a problem with your lines or telephone system. There is nothing to report or fix on your services. As the person calling you to report the problem to the provider of their service.