Mind the linguistic gap!
Jonnie Robinson, Lead Curator for Sociolinguistics writes:
Commuters travelling to and from London through Metroland and beyond face a daily choice of tube or train: Chiltern Turbo or Metropolitan Line. So - shall I go home today by tube from Baker Street via Moor Park to Amersham or catch the train from Marylebone to Birmingham Moor Street calling at Beaconsfield? For most I suspect the decision is based on relative cost, speed, comfort and convenience of final destination. Following the Metropolitan Line's upgrade, including new onboard announcements, I wonder if linguistic preferences also come into the equation?
For residents of Buckinghamshire two stations above are superfluous (Moor Park and Birmingham Moor Street). They are only significant in that they both contain the word moor, the pronunciation of which has been changing in RP and some other British English accents since the middle of the 20th century. Older descriptions of RP and speakers of more conservative RP varieties interpret the vowel here as a diphthong (i.e. two adjacent vowel sounds such that moor sounds a little like 'moo-uh'). Younger speakers and more recent descriptions of RP favour a monophthong (i.e. moor rhymes with maw). This transition from diphthong to monophthong affects a group of words known to linguists as the CURE lexical set (e.g. poor, sure, tour and during). Although a relatively low frequency English vowel, a diphthongal pronunciation can contribute to an impression of 'old-fashioned', 'elegant' or perhaps even 'posh' speech, depending on our point of view.
British Library sound recordings provide wonderful evidence of this kind of linguistic change. The following recording from the Millennium Memory Bank (BBC, 1999) illustrates the diphthong variant on the word tour:
The recently created VoiceBank (BL, 2011) includes a substantial dataset of present-day RP speech. A preliminary audit of a random sample of RP speakers' pronunciation of the word poor shows an overwhelming preference for the monophthong, although the first speaker below shows the diphthong continues to survive:
Hang on a minute - what's all this got to do with commuting? Well, intriguingly, the station announcement at Marylebone station and onboard Chiltern Line trains uses the more 'conservative' diphthong in Birmingham Moor Street, while the Metropolitan Line announcements at Moor Park use the more 'contemporary' monophthong. The announcements may be recorded scripts or automatically generated from a list of pre-recorded phonemes, but clearly the underlying phonetic systems differ in their representation of this vowel sound. So - tube or train tonight? The choice is yours (yew-uhs or yaws)!