Prince William's cut-glass accent is a little less polished than Kate Middleton's The changes in the accent can even be noted in the Royal Family. While older members such as the Queen and Prince Charles still use traditional RP, younger royals like the Duke of Cambridge and Prince Harry now speak the younger form. In fact, such are the changes that linguists have suggested that the Duke of Cambridge's accent is now less refined than that of his wife, who speaks in more traditional RP. The changing nature of the accent has been highlighted by an ongoing study at the British Library. Researchers there have amassed a database of 15,000 readings by members of the public of the children's book Mr Tickle. The story book, by Roger Hargreaves, was chosen because it provides a good range of all the vowels and consonants that vary according to accent. Those taking part could submit a recording online, or by visiting the library. They believe it gives an excellent sample to record the changes that RP, described as the regionally neutral middle class accent of England, is undergoing. Jonnie Robinson, a curator and linguist at the library, said: "RP isn't dying out. It is simply changing as a linguistic entity. Just like a Yorkshire accent now will be different from one from a century ago, it is still defined by the same things. RP has changed quite dramatically over the last 50 years. Now, people are speaking a more relaxed, modern RP. Speakers of the more modern variety include Fiona Bruce and Emily Maitlis, the BBC broadcasters, while more traditional RP speakers include Joanna Lumley, the actress, Jeremy Paxman, the broadcaster, and Boris Johnson, the mayor of London. Mr Robinson suggested that also among "modern RP" speakers were the Prince Harry and the Duke of Cambridge, but possibly not his wife, whose pronunciation of certain vowel sounds are more traditional RP. He added: "The Duchess of Cambridge is arguably posher than her husband and his brother. William and Harry are more modern in their interests. They are quite clearly still RP, but not particularly posh RP. Kate has focused on her voice. She always strikes me as more careful. They are both clearly RP but given that he is a royal and she isn't, you would expect him to be posher, but I'm not sure he is. Previous analysis on changes to RP have focused on the more obvious use of the glottal stop, replacing the "t" sounds in words like "bottle." But linguists believe that is a more self-conscious affectation by RP speakers, to make their voice less posh, than the loss of the dipthong. Although it is one of the most scrutinised and best known of all English accents, RP has only ever been spoken by around three per cent of the population. Many middle class people in southern England with seemingly neutral accents share many of its aspects in their speech, but use some regional vowel sounds that distinguish them from true RP speakers. The accent is actually relatively young in linguistic terms having emerged from nineteenth century public schools. The advent of broadcasting technology and the BBC ensured its cultural spread in the early twentieth century, as it became the standard voice heard on the corporation. It was adopted by the expanding middle class and represented an aspirational symbol of social status. But just as the BBC has encouraged a wider range of accents in recent decades, experts have claimed RP has been on the decline, in the face of a rise of so-called estuary English, a resurgence of other regional accents and the creep of American pronunciations and intonation. Melvyn Bragg, the broadcaster, is among those to have predicted its demise, having studied the accent for a BBC Radio 4 series. What type of RP do you speak? Poor Poo-er - Traditional Paw - Modern Mature Matchewer - Traditional Matchoor - Modern Beer Bee-er - Traditional Bih - Modern Near Knee-er - Traditional Nih - Modern Foot Fut - Traditional Fooot - Modern Roll Rowel - Traditional Rowol - Modern Old Eweld - Traditional Oweld - Modern Hair Heeh-er - Traditional Heeh - Modern Good Good - Traditional Gud - Modern