I don't know either CBS or Robson Green and I've never Heard them speak so I don't really know what Symptoms means, when he says "it sounds fake". There's a northern expression, "putting it on", which I've Heard people use when referring to people who are deemed to behaving in a manner above their station - so to speak. The same expression can be used when speaking of changing the way you speak. I wonder if this is what you meant - that they speak in a manner which we would normally connect with a higher social class? In that case we're not talking about dialects but sociolects. A sociolect has nothing to do with geographic origins, unless the speaker is adopting Another dialect to fit in with a Group for example a Geordie who moves to Yorkshire and starts to speak with a Yorkshire dialect at work but retains his Geordie dialect at home with the wife. Much depends on the context in which speech Changes are made. There are individuals who change their way of speaking several times a day depending on who they are talking to. They make these Changes for several reasons: to aid Communication: Changes in speed of talking, dialectal reduction/removalto show their sense of belonging, or wanting to belong to, a certain Group: adopting dialectal features, use of jargon (especially in the working environment), use of slang and swear words (in certain age Groups and social Groups)to diminish a sense of dialectal inferiorityto increase a sense of dialectal superiorityAll of these Changes can be made by conscious effort on the part of the speaker but they can also occur naturally, triggered by something in the situation. . We have to take into consideration the context in which the Changes are made. For example, a speaker with a strong Northumbrian dialect, who speaks broad dialect at home, at work and in social situations can change his speech to aid Communication when speaking to a doctor because it's important that the doctor understands the problem. Put the same person on radio to appeal for funds for his sports club and he'll change his way of speaking again - because he wants to get his message across to as many as possible. Give the same person a new neighbour from the home counties and he'll start speaking with him in dialect but will most likely start to reduce his own dialect and even adopt a bit of the new neighbour's just to aid Communication and to make the neighbour feel at home. These are natural Changes to aid Communication. The speaker isn't often aware that they are making Changes. However, if this same speaker then goes to the social club and starts speaking to his mates in the same way he's talked to the doctor, on the radio and with his neighbour it's not about aiding Communication. They already understand his dialect. There's no need for change. Then one of two things has happened: he's "putting it on" or he's adapted to a new way of talking because of the frequent use. He'll be speaking standard English with an accent. The accent is hard to lose. Not impossible but hard. So each of you is correct in some way.