The formation of these regional/socio-economic dialects is the same form of language contact that has given rise to Scottish English.
ðə fɔːɹmˈeɪʃən ʌv ðiːz ɹˈiːdʒənəl slˈæʃ sˈoʊsɪˌoʊˌiːkənˈɑːmɪk dˈaɪəlɛkts ɪz ðə sˈeɪm fˈɔːɹm ʌv lˈæŋɡwɪdʒ kˈɑːntækt ðæt hɐz ɡˈɪvən ɹˈaɪz tə skˈɑːɾɪʃ ˈɪŋɡlɪʃ.