The position of the tongue during rest and its relationship to subsequent pre-acoustic speech movements have shed light on speech motor planning. They may find applications in technologies such as silent speech interfaces. Palo [“Measuring pre-speech articulation,” Ph.D. thesis (Queen Margaret University, Edinburgh, 2019)] found that the duration of pre-acoustic speech movements are strongly correlated with acoustic utterance duration, but it remains an open question whether this correlation is modulated by different rest positions. This study investigates variability in rest position among children and adults, and examines whether rest position affects pre-acoustic speech movements and their correlation with acoustic utterance durations. [This work has been supported by a personal grant from The Emil Aaltonen Foundation (Palo) and by NSF Grant No. 1551131 (Lulich).]