This paper investigates an unexplored variation pattern in Modern Hebrew: unstressed /a/-raising. While existing research confirms that unstressed Hebrew vowels are typically shorter than stressed vowels, data that we elicited from 30 Hebrew speakers show that unstressed /a/ is often realized higher as well. While this is in line with the general articulatory bias to raise non high vowels when their duration is short (Flemming 2004; Cohen Priva and Strand 2023), for some of the speakers the tendency appears to be phonologized. Furthermore, we show that there are considerable differences in the degree to which speakers yield to this articulatory bias, with many appearing to be able to resist the phonetic pressure altogether. We argue that these findings are not consistent with a view of sound change in which yielding to contextual effects is random (Ohala 2003). We therefore call for a combined model that extends current variationist approaches, integrating the extent of speakers’ compliance with phonetic biases as an additional parameter in the study of sound change.