Speech perception is informed by inputs beyond audition: perturbing the speech articulators directly or stimulating their cortical representations influences the perception of incoming speech sounds. It is unclear how the brain encodes articulatory representations and uses them in speech perception. My goal is therefore to understand such interactions between auditory and sensorimotor systems – using electroencephalography to map brain activity during a categorical speech perception task. In this study, participants classified spoken vowels under two conditions: baseline, and with a plastic tube between the lips. Preliminary results reveal differences in perceptual encoding of speech sounds when the articulatory perturbation is present: the perceptual boundary between phonemes is slightly shifted in the direction of participants' orofacial configuration (more stimuli perceived as /œ/ vs. /u/), and neural responses to speech stimuli are differentiable between conditions. Further, auditory brain regions display stronger functional connectivity with the ventral sensorimotor cortex during the manipulation compared to baseline, potentially reflecting the recruitment of articulatory representations to guide phonetic encoding. Overall, results support an active role of the sensorimotor system in guiding speech perception.