OK, there's definately been a voice fault on my line since the first signs on Saturday reported above. Problem is it's intermittent.
I powered the modem off on Saturday night, and didn't power it back on until late Sunday night as I had been attending a wedding (no,not mine!)
This morning a voice call I made had very noticeable interference, to the extent that I had to apologise to the other party. And, in current stats there have been no less than 13 resyncs in the 2hr period between 11:29 and 13:28, after which I switched the modem off in the hope of preventing DLM from taking action (probably already too late by the time I discovered it), and looked out the 'wired testing phone' that we have all purchased and keep specifically just for such testing purposes (don't we
?)
Plug the phone directly into the NTE5 test socket and of course it's gone all quiet again! Repeat the test several times while restoring the setup back to 'normal' and of course it remain quiet. Which it will do probably until tomorrow morning, I guess, when I shall be hot-foot back to the test socket with the phone ready to phone ... um who, exactly, I'm not quite sure at this point ... and hopefully will get the fault reported while it's still noisy.
Why I am unsure is that Plusnet sent the takover request for the line to BTOR on 1 Apr, but the line won't actually be transfered until 16 Apr (why for a database update is beyond me). BTOR notified BE, who believe that Plusnet now 'control' the line, even though they will continue to bill me until then for it, both rental and usage; but I suspect Plusnet might say it's not theirs yet. So hopefully the noise will hang around long enough for me to try to report it first to BE, and then Plusnet if necessary, and possibly BE again, I don't know!