Binaural listening is an immersive audio technique that aims at recreating a realistic sound scene to the listener through headphones. Externalization refers to the impression that virtual sources come from outside the head (as in real life) and a good externalization is crucial for the binaural listening to be convincing. An efficient way of improving externalization is to pair the binaural listening with a head tracking device, capable of modifying the audio content according to the head movements of the listener. The aim of this study was to find neurophysiological markers of the externalization sensation by performing both an auditory evoked response potential (aERP) anaysis and a behavioral analysis. The EEG of subjects listening to binaural stimuli was recorded, then the subjects had to evaluate externalization. Depending on the conditions, the subjects were asked to perform head motion or to remain static and the head-tracking device was either active or inactive. In the condition with head movements and with active head tracking, the subjects reported a better externalization than for other conditions. Performing a head movement, whether the head-tracking was active or not, enhanced the amplitude of ERP components after 100 ms.