From the 1600s onwards, however, it became fashionable in and around London to lengthen the vowel sound in a small number of words where the precedes the consonant sounds , and . Thus in seventeenth century London pat would have been pronounced with the short ‘a' vowel, but path and other similar words would have contained a slightly lengthened version of the same vowel. We can describe this sound as ‘aa’. At a later date, however, speakers in London and the Home Counties started to adopt a completely different long vowel making this new pronunciation distinction even clearer. They retained the original short vowel for words such as rat, but began to use a vowel rather like the sound we are asked to produce when a doctor examines our throat in words such as raft. This vowel sound we can characterise as ‘ah'.