Some of the most prominent findings regarding the documentation of linguistic change and how social and linguistic factors affect change as it moves through a community have come from the project on Linguistic Change and Variation in Philadelphia (LCV) conducted in the 1970’s, and the analysis of these data (Labov 1994, 2001). This dissertation is a re-study of the Philadelphia speech community, focusing on the effects of sex on language change. The male-led change of the centralization of the nucleus of /ay/ before voiceless consonants (ay0) was selected as the focus of this dissertation. In addition to this variable, this dissertation investigates (aw) and (eyC) through a real time study using the methodology adopted by the LCV. A representative set of vowel tokens were measured and normalized for each subject, and these data were used in multiple regression analyses to identify changes in progress and possible social factors affecting the changes. In order to explore gender further, a 3-part Gender Index was created using sex, sexual orientation and childhood/adolescent socialization experiences. All three variables are still involved in change in apparent time, which is supported by real time analyses. The raising of (ay0) no longer shows a significant sex difference or social stratification. (aw) shows a reversal of the direction of the change in F2 as posited by the LCV, and the real time data confirm this analysis. (eyC) shows change in vowel height, rather than change in F2 as identified in the LCV data. Like (ay0), (eyC) does not show sex differentiation. While the Gender Index does not show significant effects predicting vowel production for any of these variables, sexual orientation does: lesbian women are leading the changes of (aw) and (eyC), while gay men show some resistance to these changes. A matched guise test shows that Philadelphians evaluate the linguistic behavior of women and men on different scales with respect to (ay0). This dissertation shows that language change can exist without sex differentiation, and that sexual orientation is a significant social factor in language change.