BT 1571 sounds like a dalek (underwater)

puddy

We moved here in June and set up 1571 as usual. It was ok initially but now the voice on the messages and the actual messages themselves sound like a dalek who is underwater, its very difficult to understand a lot of what the messages say. Its v frustrating.
Has anyone else had this, I think this is our 'internet line', but as far as I remember when I switched to the 'landline' it did the same thing (cant remember how to switch it on again as we dont use it now)