The claim that high-frequency words tend to undergo regular sound change faster than less frequent words is common in Exemplar Theory literature. This paper examines the effect of word frequency on F2 of short vowels in the region of American English subject to the Northern Cities Vowel Shift (NCVS). I find that more frequent words appear to have more centralized vowels - higher F2 for back vowels, and lower F2 for front vowels - regardless of the direction the vowel is moving in the NCVS. I interpret this result as supporting, rather than the strong claim that high-frequency words undergo sound change in general faster, an observation by Phillips (1984) that high-frequency words undergo specifically lenition faster.