The Atlas of North American English, based on the study of cities over 50,000 population, shows that American regional dialects are becoming increasingly different as a result of ongoing changes in their vowel systems, leading to considerable miscomprehension across dialects. An understanding of this process calls for studies of many more communities and speakers. However, currently used methods of analysis require several days or weeks to accurately define the vowel system of a single speaker. This project is based on an accelerated method that produces ten times as much data in one hundredth of the time required, using automatic alignment of the sound wave and transcriptions. Methods will be developed for automatically measuring each vowel in the transcript with an error rate equal to or lower than that of manual measurement. These techniques will be tested on a very large database on change in the speech of a metropolitan community, a series of interviews recorded annually in Philadelphia neighborhoods from 1973 to 2008.
Dialect diversity is one of the major factors limiting the success of automatic speech recognition and provides a major challenge for our understanding of the causes of language change. The methods developed in this project will serve to accelerate sociolinguistic analysis across other communities and other languages. Findings from the analysis of the Philadelphia database will contribute to the understanding of gender differentiation in language change in progress, the reversal of the direction of change, and the diffusion of change across neighborhoods.
THE USE OF NEW METHODS OF AUTOMATIC VOWEL MEASUREMENT TO STUDY SOUND CHANGE IN PHILADELPHIA Sound change and earlier studies of the Philadelphia dialect Recent studies of everyday speech in the regional dialects of the United States have shown that ongoing sound changes are increasing the differences between them. These steadily increasing sound changes are the cause of considerable misunderstanding across and within dialects. The Philadelphia dialect is a striking example, where 12 of the 18 vowels were found to be involved in change in studies supported by NSF in the 1970s. A parallel series of neighborhood studies were conducted by University of Pennsylvania students in a course on "The Study of the Speech Community". The course was taught yearly from 1972 to 1994, and every two years from 1994 to 2010. A total of 1,087 speakers were interviewed in 59 neighborhoods, with dates of birth from 1888 to 2000. Earlier methods for analyzing the vowel system of an individual required approximately 40 hours to select and measure the vowels, typically yielding 300 vowel measurements. The research project developed a computer program which made this process automatic, making 20 times as many measurements in a hundredth of the time required and with greatly increased accuracy. The results of these measurements show that two of the traditional sound changes have continued in the same direction for over 100 years. The vowel of mate, fate and sane is moving steadily towards the vowel of meet, feet and seen. The vowel of right, like, sight shifts towards the center of the mouth, so that it begins with the sound heard in the a of about. Three others have sharply reversed the direction of change, beginning with speakers born in 1960s and later. These involve the vowels of go, now and move. Women were clearly in the lead at the outset of these changes, but have also led in the reversal, so that there is no significant difference by sex among the youngest speakers. These dramatic changes in the Philadelphia vowel system show some features of the city’s dialect becoming stronger, and others weaker. What explanation can be put forward for these contrary movements? It is common to explain the first kind of movement by a tendency to strengthen symbols of local identity, but one would have to explain the second by a contrary tendency. The position of Philadelphia in a national perspective shows that there is a common thread that unites these changes. In terms of its traditional dialect, Philadelphia was the northernmost of the Southern cities. It was a part of the Southeastern Super-region that includes the South and the southern half of the Midland, including cities like Columbus, Cincinnati, Indianapolis, Springfield and Omaha. The reversal of the three sound changes moves Philadelphia away from those Southeastern dialects and towards the Northern dialects of western New England, the Hudson Valley, northern New Jersey and northeastern Pennsylvania. The sound changes being strengthened are common features of the North. In the most general view it appears that since 1960 Philadelphia has turned away from its Southern heritage and joined the North. Its northern border includes northern New Jersey, the Allentown-Scranton area, and beyond the Hudson Valley and northern New England. New York City, on its northeastern border, is not a factor in this development, since those features that Philadelphia shares with New York City are also being sharply reversed. As a complex system, language frequently shows a series of compensating adjustments that maintain maximum efficiency in its communicative elements. This study shows that social forces can operate in a different direction, driving change determined by the perception of social identity on a very large scale. The methods developed for automatic vowel measurement have been made available for general use on the web site http://fave.ling.upenn.edu.
