WE are living in an alternative reality. The Nazis are running Britain, but the biggest problem isn’t the judicial executions, or the concentration camps, or the collaborators. It’s the mmmmbblin. The muuuumbling. The indistinct speaking.

You will know what I mean if you’ve seen any of SS-GB, the BBC’s new drama based in an alternative-reality Britain in which the Nazis won and we lost. It is well made and beautifully shot, but as one letter writer put it in The Herald this week: “I understood the German better than I did the English and that is without subtitles.”

This problem of mumbling seemed to start with the BBC’s big adaptation of Jamaica Inn three years ago, which again looked great, but at the time I remember asking why no-one questioned the central problem with the show. Why did no-one say: "Hang on, it looks great but I can't understand a single word that man is saying?" Are we so obsessed with how something looks now that the words are irrelevant?

Other shows have been accused of the same problem and a number of theories have emerged. One is that producers and directors watch the playback of their programmes on the very best, high-end technology with good speakers so they can make out every word and don’t realise there’s a problem.

Another theory is that modern televisions are to blame. The fashion in recent years has been for flat-screen sets, which is fine but the speakers tend to be small and tinny.

But the real explanation for the mumbling has nothing to do with technology and everything to do with how acting has changed. Fifty years ago, when an acting student arrived at drama school with a regional accent or an indistinct way of speaking, it was very quickly drummed out of them. The pinnacle of the profession was Laurence Olivier whose delivery was so beautiful clear and precise you could hear every syllable ting as he spoke.

That way of talking has now gone out of fashion, and we probably don’t want to go back to the days when everyone on television sounded very similar – clear but similar. However, we have gone too far the other way and eschewed that old-school received pronunciation and celebrated “real” ways of talking to the point where no one can actually understand what is being said.

The other problem is the diminishing power of the director and the increasing power of the actor. Again, 50 years ago, television directors were the powerhouse; they were the ones who made the decisions and told actors to do a retake if necessary. These days, the producer, and his or her big actor star, tend to hold the power and the director has a much more functional role ie. get the programme out. They are much less likely to question their actors or ask them to do a line again if it was inaudible.

All of this means that the mumbling problem is not going to go away until we have a rethink about how actors are told that one of their jobs is to be understood. You can point the best microphone in the world at an actor, but if the words are slopping lazily over their lips in an attempt to be “real”, then there is nothing much we can do about it.