EARLIER this week, while joyriding on the internet and looking for trivia on my favourite TV programmes, I came across something that bewildered me.

It was a website for fans of Inspector Morse and referred to “Morse’s faithful sidekick, Welshman Sergeant Lewis”.

Whoever wrote this can’t have paid much attention – or perhaps needs a hearing aid.

Lewis isn’t Welsh. He’s from Newcastle. He refers to his home town regularly. And the actor who played him, Kevin Whately, is from Hexham. How could anyone get it so wrong?

Perhaps some southern English people are less well attuned to regional accents than people from the regions themselves.

It’s probably why London advertising agency WCRS made the Royal Navy recruitment ad featuring a Carlisle sailor, and dubbed his voice into a broad Geordie accent, presumably assuming that no-one in the south of England would notice the difference.

Or maybe some people are just deaf to accents. A friend and former work colleague of mine is from Kerry in south-west Ireland – about as far in Ireland as you can get from Belfast.

And yet another of our colleagues said she couldn’t tell our accents apart, which surprised us.

Irish accents don’t vary as much as English ones. North-eastern English accents are quite distinct from Cornish ones. But they do differ, and we couldn’t see how someone didn’t notice.

One of the major advantages of possessing an Irish accent of any variety – and one that applies to most Scottish accents as well – is that they are much less readily identified with a certain social class.

Yet English accents are often taken, rightly or wrongly, to indicate not just class but other attributes.

Irishman George Bernard Shaw once made the observation: “It is impossible for an Englishman to open his mouth without making some other Englishman hate or despise him.”

And a new survey by researchers at the Sutton Trust has found that this has hardly changed in 50 years.

Northern English accents, for example, were rated highly for friendliness and trustworthiness.

But southern accents were said to indicate greater intelligence, ambition and wealth.

This made me rather cross. One of the most intelligent people I know is a professional musician, who also has a science degree from Cambridge, has studied at least four languages, does cryptic crosswords and is frighteningly well read, far more than me. I live in fear that she’ll conclude sooner or later that I’m a bit of a phoney.

And she’s from County Durham. She admits her accent has softened a bit after 30 years away from home – but it’s still noticeable in her vowel sounds, or whenever she’s recently taken a trip back there.

Any assumptions made about her based on her accent would be a million miles wide of the mark.

And I can think of plenty of southerners who aren’t very bright, but are perfectly friendly and trustworthy.

This problem is known as “accent bias”, and according to the Sutton Trust it is as widespread now as it has ever been.

It found that around 41 per cent of students with regional or working-class accents said they feared that the way they spoke would count against them.

Some felt they would need to change it when it came to interviews for jobs or places at university.

I have never contemplated trying to change my accent. It would be denying part of my identity. And I’ve always distrusted those whose accents have changed radically – including some of those I was at school with who also settled in England and now sound English.

It shouldn’t be necessary. So I find it alarming that some young people are feeling compelled to change theirs.

And it’s a prejudice I had thought might have died out by now.

Edward Heath and Margaret Thatcher had both had to adopt posh accents to get on in the Conservative party of the 1960s, but by 2010 George Osborne was trying to assume a less posh voice.

Osborne’s voice change was just as fake. But it did at least represent a reversal. Yet the study also said that public perceptions of accents and what went with them were unchanged.

English accents used to be mapped very closely to the boundaries of the old Anglo-Saxon kingdoms of Northumbria, Mercia, East Anglia and Wessex.

Then influences from elsewhere shifted them – so that the unique Scouse accent seems to be s blend of Lancashire and Irish.

Accents will always shift and change, and none of us need to lose our own.

What we should lose is the snobbery and prejudice in our unfair attitudes towards them.