Map 1. The merger of /o/ and /oh/: invariant responses in production and perception.
Large map with full information on Telsur subjects
Map 1 shows all speakers who show either a clear and consistent distinction or a clear and consistent merger of /o/ and /oh/. between /o/ and /oh/ in speech production, and in minimal pair tests. The speakers designated by blue circles say /o/ and /oh/ words with distinctly different vowels, and respond in minimal pair tests that they are clearly different. The speakers designated by red circles say /o/ and /oh/ words identically and say that they are 'the same' in minimal pair tests. Small grey squares indicate speakers who show some type of variability or inconsistency. The data include environments before nasals (Don vs. Dawn), before /t/ (cot vs. caught ), and before /k/ (sock vs. talk). It also includes a more limited number of cases where the distinction was elicited before /d/ (sod vs. sawed).
There are three main areas where the merger was initiated independently: Eastern New England, Western Pennsylvania, and the West. The red circles showing invariant merger are most consistent in these areas; it is apparent that the merger is still in progress in the West, and considerable variation is shown in the largest cities (Los Angeles, the Bay Area). If we compare this situation to the Linguistic Atlas records of the 1940's (Kurath and McDavid 1961), the most rapid expansion is found in the areas adjacent to Western Pennsylvania. The merger is extensive in eastern Ohio, and a new area of expansion, not reported before, appears in the adjoining Appalachian areas of West Virginia and Kentucky. The independent merger in Eastern Pennsylvania which Herold discovered (1980) does not show here as an invariant merger, but rather as a consistent pattern of variability.
It is well known that the merger is a consistent feature of Canadian English, but TELSUR results do not yet include Canadian data.
Since mergers regularly expand at the expense of distinctions (Labov 1994: Chs. 10-13), and the merger has been in progress for at least a hundred years, one might predict that it will soon cover the whole country. However, there are reasons to think that this may not be the case. The areas with a solid distribution of blue circles show substantial resistance to the progress of the merger. There are two such areas. The inland North, bounded by the lexical isogloss shown in light gray, is one such solid area. This situation will be illuminated further by maps that show the progress of the Northern Cities Shift. The primary characteristic of this area is that short /a/ forms a single phonological unit, and under the tensing operation that is the first step in the Northern Cities Shift, all short /a/ tokens move forward and up, leaving a gap in low front position. Short /o/ then moves forward as long open /o/ moves downward. In the North Midland, south of the lexical line in Map 1, we do not find such wholesale fronting of short /a/ and /o/, and in most areas there is a widespread tendency to the merger. The same can be said for the transitional area to the west, in Iowa and Missouri.
We also find a solid resistance to the merger in the heavily populated Mid-Atlantic States. Here there is no forward movement of short /a/--instead, short /a/ is split and some tokens remain in low front position while others are tensed and raised. But in these areas, /oh/ is not lowered and fronted, but is raised and backed, creating a very great phonetic distinction between /oh/ and /o/.
The eastward expansion of the merger is not as pronounced as one would believe from the only earlier national map of a phonological feature extent: the results of enquiries with long distance telephone operators in 1966 (Labov 1991). At that time, the transition zone ran through Wisconsin, Iowa, Missouri, Oklahoma and the panhandle of Texas. In Map 1, the transition zone is even slightly further to the west.
New variation in the South
The Southern States generally show a distribution of blue circles, with only an occasional red circle. Yet the pattern is not by any means as consistent as in the North or the Midl-Atlantic States. In several different ways, the pattern of /o/ and /oh/ distinction characteristic of the South is beginning to weaken; this topic will be explored in later maps.