Maybe it's just me but every time that woman says "couples" or "judges" it's like someone stabbed me in the temple with a needle.

Get rid of her and Brucie and it would be a better show.

You mean: cupples and juddddjiz.

Wonderful is it not? The splendid regional variety of speech.

Annoys me too, but it seems to be tidal, sometimes she gets it right others I think she puts it on.

She's spent enough time in London to lose the hard "Northern vowel sounds." Many other Northeners on TV have a slight trace of their native accent, but it has become softened with absence over time.
It's a gimmick, her version of the "Cilla Black" accent.
A woman who's lived in the home counties for decades, wouldn't be able to find Liverpool on her own and saves the accent for TV appearances.

Tess and Vernon Kay both use the very noticable Lancashire vowel sounds, but only on certain words, even then they sometimes forget to do it.
This makes them sound as false as they look.

I am from the north (not far from Bolton) and the way that she says COUUUUPLES annoys the hell out of me

That doesn't annoy me, Bruce and Len do though.

Although born in Stockport, Tess actually grew up in Derbyshire.

Vernon on the other hand is Lancastrian born and bred - although these days his place of birth (Bolton) is officially part of Greater Manchester.