Jonnie Robinson, Lead Curator for Sociolinguistics writes:

This month we've uploaded linguistic descriptions of conversations about local speech in Bradfield, Purley on Thames and three recordings in Reading (one with work colleagues, one with young British Asians and one with a Bajan family). Together they constitute the set of BBC Voices Recordings made by BBC Radio Berkshire. The descriptions list the participants' responses to  a set of prompt words and, in the case of the Bajan family and Purley on Thames also include detailed descriptions of the grammar and phonology of the speakers.

It's fascinating to see how these two apparently unrelated recordings illustrate the same linguistic process: dialect shift. Not surprisingly, the Caribbean heritage of speakers born in Barbados, but now living in Reading, is reflected in their accent. They all use several pronunciations here that are typical of Bajan English, such as the so-called GOAT vowel in words like stone, road and know. The younger generation - born and brought up in Reading - vary between this pronunciation and a more obviously southern British variant. Listen, for instance, to Kevin fluctuate between the two variants in the same utterance:

1:18:46 yeah, you call him a  'poser', "he's a poser, man, look at he posing with cheap gold and fake gold and designer clothes"

His initial pronunciation of the word poser contains a typical southern English vowel sound, but he subsequently uses a Bajan-like vowel on the second instance of poser, posing, gold and on the word clothes. This illustrates perfectly how dialect contact produces incremental change within a single family - one pronunciation is used consistently by older speakers, but competes in the next generation with a more dominant and/or socially prestigious variety in the community.

The recording in Purley allows us to observe the same process of dialect shift over three generations, albeit in the context of a well-established local family and on a  different linguistic variable: rhoticity - i.e. the presence or absence of a <r> sound after a vowel in words like start, letter and nurse. The oldest speaker (b.1928) invariably pronounces this <r> sound here, while his son (b.1947) varies between including and omitting <r> in this environment.  In contrast the two younger speakers (both born in the 1970s) consistently omit this <r> sound, showing that the loss of postvocalic <r> is completed over two generations in this family.

Although this process of change occurs on different pronunciation variables in each recording (and is presumably prompted by different reasons), it nevertheless shows how a linguistic feature gradually 'shifts' in prominence across successive generations of the same speech community. For speakers like the Bajan family who have relocated to a completely different country, the older speakers are outnumbered by speakers of the local dialect so the younger generation naturally accommodates towards their local peers. The loss of rhoticity in the Purley family, however, reflects a trend that has been noted across southern England over the last century, and can be attributed to continuous waves of migration of non-rhotic speakers, especially from London, out into the surrounding Home Counties like Berkshire.