Figure 2.6 International Phonetic Alphabet and the author’s vowel system
The linguistics lab at the University of Pennsylvania has been the site of
many large-scale studies of change in progress, but the biggest and most
exhaustive study, still ongoing, probably is the NCCS study. Simply put, six
vowels are on the move, as seen in Figure 2.7 and 2.8.
Figure 2.7 Geographic areas participating in the Northern Cities Chain Shift
Source: Adapted from Labov et al. (2006: 204)