of the cot vowel, it results in lengthening and perhaps raising, merging the more recently separated vowel into the vowel in the following environments: before many instances of , , and particularly (as in Austria, cloth, cost, loss, off, often, etc.), a few instances before (as in strong, long, wrong), and variably by region or speaker in gone, on, and certain other words. The standard accent of southern England, Received Pronunciation (RP), has evolved in other ways compared to which General American has remained relatively conservative. Examples include the modern RP features of a trap–bath split and the fronting of , neither of which is typical of General American accents. Moreover, American dialects do not participate in H-dropping, an innovative feature that now characterizes perhaps a majority of the regional dialects of England. Innovative phonology However, General American is also innovative in a number of ways: Unrounded : The American phenomenon of the vowel (often spelled in words like box, don, clock, notch, pot, etc.) being produced without rounded lips, like the vowel, allows father and bother to rhyme, the two vowels now unified as the single phoneme . The father–bother vowel merger is in a transitional or completed stage in nearly all North American English. Exceptions are in northeastern New England English, such as the Boston accent, as well as variably in some New York accents. Cot–caught merger in transition: There is no single American way to pronounce the vowels in words like cot (the ah vowel) versus caught (the aw vowel), largely because of a merger occurring between the two sounds in some parts of North America, but not others. American speakers with a completed merger pronounce the two historically separate vowels with the same sound (especially in the West, northern New England, West Virginia, western Pennsylvania, and the Upper Midwest), but other speakers have no trace of a merger at all (especially in the South, the Great Lakes region, southern New England, and the Mid-Atlantic and New York metropolitan areas) and so pronounce each vowel with distinct sounds . Among speakers who distinguish between the two, the vowel of cot (usually transcribed in American English as ), is often a central or advanced back , while is pronounced with more rounded lips and/or phonetically higher in the mouth, close to or , but with only slight rounding. Among speakers who do not distinguish between them, thus producing